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The Southern Sky GuideThird EdiTion

Both novice and advanced skywatchers will value this comprehensive and easy-to-use guide to the brilliant and ever-changing sights of the southern sky by night.

Readers are introduced to the many and varied objects in the sky and their movements and changing appearances, as well as the ancient myths and legends entwined around the groupings of stars.

Featured in this book are two groups of sky charts, designed so that readers can move easily between them. The 24 Skyviews show the appearance of the whole night sky every two weeks (or at each hour of sidereal time). The 20 Sky Charts show particular areas of the night sky in detail and are accompanied by explanatory text.

This new edition features:• digitallyre-drawnSkyviews,SkyChartsandmapofthesurfaceoftheMoon• atableofplanetpositionsupto2017.

David Ellyard is an award-winning freelance science writer and broadcaster with a life-long passion for astronomy.

Wil Tirion is a Dutch celestial cartographer and is widely regarded as the leading exponent of his art in the world.

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S_Sky_Guide_TEXT_3ed_00.indd 2 7/5/08 11:30:09 AM

TheSouthern Sky

GuideThird EdiTion

david Ellyard and Wil Tirion

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CAMBRIDGE UNIVERSITY PRESS

Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo

Cambridge University Press

The Edinburgh Building, Cambridge CB2 8RU, UK

First published in print format

ISBN-13 978-0-521-71405-1

ISBN-13 978-0-511-47858-1

© David Ellyard and Wil Tirion 2008

2008

Information on this title: www.cambridge.org/9780521714051

This publication is in copyright. Subject to statutory exception and to the

provision of relevant collective licensing agreements, no reproduction of any part

may take place without the written permission of Cambridge University Press.

Cambridge University Press has no responsibility for the persistence or accuracy

of urls for external or third-party internet websites referred to in this publication,

and does not guarantee that any content on such websites is, or will remain,

accurate or appropriate.

Published in the United States of America by Cambridge University Press, New York

www.cambridge.org

eBook (EBL)

paperback

ThE panorama of ThE niGhT Sky 1Starting with the stars 1Star stories 1The stars by name 6Brighter and fainter stars 6How far away are the stars? 6Stars of many colours 7Sizes and distances in the sky 8More than one at a time 8Stars that change 8The heavens in motion 9mapping the sky 9The line around the middle 9The grid of the sky: (a) declination 12The grid of the sky: (b) right ascension 12Sun and moon 12The ecliptic and the zodiac 12Sky change throughout the year 13The moving Moon 13Eclipses 14The face of the Moon 14The planets 14The movements of the outer planets 14The movements of the inner planets 16Which planet? 16The waltz of the planets 16Satellites, comets, meteors, minor planets 17a variety of sights 17Stars get together 17The Milky Way 18Nebulae, dark and bright 18Nebulae beyond 18

ThE SkyviEWS 21Using the Skyviews 21The Skyviews 1–24 23

ThE niGhT Sky in dETail 47Using the Sky Charts 47The Sky Charts 1–20 48

appEndixES 89a: Using binoculars and telescopes 89B: planet positions 90

indEx 97

liST of TaBlESTable 1. The 88 constellations 2–3Table 2. The 25 brightest stars 7Table 3. Main meteor showers 17Table 4. Choosing the right Skyview 21Table 5. Planet positions 2008–2017 91–95

liST of illUSTraTionSConstellations 4–5Whole-sky map 10–11The main features of the surface of the Moon 15The Skyviews 23–46The Sky Charts 48–87

v

ConTEnTS

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vi

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1

When the night sky is dark and clear, it presents a daz zling spec ta cle. Myriads of stars, glowing patches of gas, a planet or two, the Moon in its phases, perhaps a meteor shower, an eclipse of the Moon or even a comet, all such sights are there for the taking by anyone who cares to look up.

Even when dimmed by city lights and smog, the night sky is worth a long look. The pano rama is con stantly chang ing, with the view never quite the same, even on suc ces sive nights. There is always some thing of inter est, some sight to appre­ciate, whether you are viewing with binoc u lars, a small tele­scope, or just with your unaided eyes.

Astronomy, the science of the stars, is perhaps the most ancient form of method i cal human knowl edge. To track the paths of the celes tial lights today is to retrace the steps of the first observ ers many thou sands of years ago.

Starting with the stars

Most of the things we see in the night sky are stars, vast balls of glowing gas similar to our Sun but so far away from us that they are reduced to mere points of light, scat tered mostly at random across the heavens. The unaided human eye can detect about 6000 stars under dark, clear con di tions, but less than half of those are visible at any one time.

For thou sands of years, sky watch ers in various cul tures have been group ing the stars together into unchang ing pat terns know as constellations or ast er isms (both expres sions come from Greek or Latin words for ‘star’). These change their posi­tions and orien ta tions in the sky through out the night and the year, but their shapes do not vary notice ably. You can always pick them out and together they (and the brighter stars in them) form a grid of famil iar ref er ence points across the night sky.

Nowadays, 88 con stel la tions are offi cially rec og nised. Many other con stel la tions have been devised over the cen tu ries but have now fallen into disuse. All con stel la tions have names, and the older and more spec tac u lar ones have myths and legends asso ciated with them in many cul tures. The best known of these stories are drawn from the mythol ogy of ancient Greece and Rome, tales of gods, mon sters, heroes and great deeds.

Star storiesFor example, the story of Andromeda, the maiden chained to the rock, is recounted in no less than six con stel la tions. Among the stars we find Andromeda herself, the monster Cetus sent to devour her, her rescuer Perseus, her parents

Cepheus and Cassiopeia, and the won der ful winged horse Pegasus (even though it was only periph eral to the Andromeda story).

The leg en dary quest of the Argonauts for the Golden Fleece has many memo ri als in the sky. In addi tion to their ship, the mighty Argo itself, now broken into its Keel (Carina), Sail (Vela), Poop (Puppis) and Compass (Pyxis), we also find the won der ful ram that pro vided the fleece (Aries), some of the Argonauts (Gemini the Twins, Hercules and Orpheus the Musician, through his harp Lyra), and even the centaur Chiron (Centuarus) who tutored the expe di tion leader Jason.

There are still more, if you take the figure of Ophiuchus, the man holding a serpent, to be Aescalepius, the ship’s doctor on the Argo, or the north ern figure of Draco to be the serpent that guarded the sacred grove where the Fleece hung, or Taurus to be one of the fire breath ing bulls with horns of brass that Jason had to tame. Strangely, Jason himself is not on show.

There are some vivid scenes. Orion the Hunter, accom pa­nied by his two dogs (Canis Major and Canis Minor), is in trouble with a charg ing bull (Taurus), and is unknow ingly tram pling on a hare (Lepus). Ophiuchus has his hands full with the serpent. The two cen taurs are pre oc cu pied; Centaurus is fight ing a wolf (Lupus) and Sagittarius the Archer has an arrow aimed at the fear some Scorpion. Leo recalls the Nemean Lion slain by the mighty Hercules as one of his 12 labours, and Cancer the Crab that bit his heel while he was bat tling with the many headed Hydra (and was crushed as a result). In the sky, Hercules has his foot on the head of a Dragon. So the struggle goes on.

The posi tions of some of the star groups are sig nifi cant. Crater the Cup, Corvus the Crow and Hydra the Water Snake lie close together because of the story they share (see text to Sky Chart 8). Orion, so the legend goes, met his end when stung by the Scorpion. As a result, they are on oppo site sides of the sky, one rising while the other sets.

Libra the Scales, lying between Virgo the Young Maiden and Scorpius, has links to both. As the Goddess of Justice, Virgo weighed the evi dence on the scales near at hand. But in some old lists, Libra was not its own con stel la tion but the greatly enlarged claws on the Scorpion coming close behind. In one region of the sky, all the star groups have to do with water. Most likely, this served as a cal en dar, indi cat ing when the rains would come.

Not all the con stel la tions are so excit ing. Many are quite dull, espe cially those more recently named in south ern skies which could not be seen from the Middle East in ancient times. Among these we find many sci en tific instru ments!

Constellations vary greatly in size and many are surprisingly

THE PANORAMA OF THE NIGHT SKY

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large, though this is perhaps not so surprising when we realise only 88 cover the whole sky. The largest of all (though not otherwise spectacular) is Hydra at more than 1300 square degrees, six or seven times bigger than your hand at arm’s

length. Virgo is not far behind, and half a dozen are 1000 square degrees or more. At the other end of the scale, the Southern Cross is less than 70 square degrees in size, and half a dozen thumbs will hide it.

2

Table 1. The 88 constellations

Size(square Monthwhen GotoPropername Meaning degrees) 25brighteststars highestat8p.m. Chart

Andromeda The Chained Maiden 722 November 13Antlia The Air Pump 239 April 8Apus The Bird of Paradise 206 July 3Aquarius The Water­Carrier 980 October 12Aquila The Eagle 652 Altair August 19Ara The Altar 237 July 3Aries The Ram 441 December 13Auriga The Charioteer 657 Capella February 15Bootes The Herdsman (or 907 Arcturus June 17 Waggoner or Ploughman)Caelum The Engraving Tool 125 January 1Camelopardalis The Giraffe 757Cancer The Crab 506 March 15Canes Venatici The Hunting Dogs 465 June 17Canis Major The Big Dog 380 Sirius, Adhara February 7Canis Minor The Little Dog 183 Procyon February 7, 15Carpricornus The Sea­Goat 414 September 11Carina The Keel (of Argo) 494 Canopus March 2Cassiopeia (mother of Andromeda) 598Centaurus The Centaur 1060 Rigil Kentaurus May 3, 9 (Alpha Centauri), Hadar (Beta Centauri)Cepheus (father of Andromeda) 588Cetus The Sea Monster (or Whale) 1231 November 5Chamaeleon The Chamaeleon 132 April 2Circinius The Pair of Compasses 93 May 3Columba The Dove 270 February 6Coma Berenices Berenice’s Hair 386 May 17Corona Australis The Southern Crown 128 July 4, 11Corona Borealis The Northern Crown 179 June 18Corvus The Crow 184 May 9Crater The Cup 282 April 8Crux The (Southern) Cross 68 Acrux, Mimosa, Gacrux May 3Cygnus The Swan 804 Deneb September 19Delphinus The Dolphin 189 September 19Dorado The Gold­Fish 179 February 1Draco The Dragon 1083Equuleus The Colt 72 September 19, 20Eridanus The River 1138 Achernar December 1, 6Fornax The Furnace 398 December 1, 5Gemini The Twins 514 Pollux, Castor February 15Grus The Crane 366 October 4Hercules 1225 July 18Horologium The Clock 249 December 1Hydra The Female Water­Snake 1303 April 8, 9Hydrus The Male Water­Snake 243 December 1

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A full list of the 88 con stel la tions, the mean ings of their names, their bright est stars, their sizes, their posi tions in the sky and on the maps in this book is given in Table 1. Pages 4–5 provide a first look at the better­known and more spec tac u lar

star groups in the form of dia grams marking their shapes and more notable stars. More details on these (and more on the stories asso ciated with them) can be found along side the Sky Charts later in this book (pages 48–87).

3

Table 1. (cont.)

Size(square Monthwhen GotoPropername Meaning degrees) 25brighteststars highestat8p.m. Chart

Indus The Indian 294 September 4Lacerta The Lizard 201 September 20Leo The Lion 947 Regulus April 16Leo Minor The Lesser Lion 232 April 16Lepus The Hare 290 January 6Libra The Scales 538 June 9, 10Lupus The Wolf 334 June 3Lynx The Lynx 545 March 15Lyra The Harp 286 Vega August 19(Mons) Mensa The Table Mountain 153 February 1, 2Microscopium The Microscope 210 September 4Monoceros The Unicorn 482 February 7Musca The Fly 138 May 3Norma (et Regula) The Level (and Square) 165 July 3Octans The Octant 291 All months 3, 4Ophiuchus The Man with the Serpent 948 July 10Orion The Hunter 594 Rigel, Betelgeuse January 6Pavo The Peacock 378 October 4Pegasus The Winged Horse 1121 October 20Perseus (rescuer of Andromeda) 615 December 14Phoenix The Phoenix 469 November 1Pictor The Painter’s Easel 247 February 1Pisces The Fish 889 November 4, 13Piscis Austrinus The Southern Fish 245 Fomalhaut October 12Puppis The Poop (of Argo) 673 February 2, 7Pyxis The Compass (of Argo) 221 March 2Reticulum The Reticule 114 December 1Sagitta The Arrow 80 August 19Sagittarius The Archer 867 August 11Scorpius The Scorpion 497 Antares, Shaula July 10Sculptor The Sculptor’s Chisel 475 November 5Scutum The Shield 109 July 12Serpens The Serpent 637 July 10, 11Sextans The Sextant 314 April 8Taurus The Bull 797 Aldebaran January 6, 14Telescopium The Telescope 252 August 4Triangulum The Triangle 132 December 13Triangulum Australe The Southern Triangle 110 July 3Tucana The Toucan 295 November 1, 4Ursa Major The Great Bear 1280 April 16Ursa Minor The Little Bear 256Vela The Sail (of Argo) 500 March 2Virgo The Young Maiden 1294 Spica May 9Volans The Flying Fish 141 February 2Vulpecula The Fox 268 September 19

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4

+10

+30 5h 2h

+30

+10

+10

–30

9h7h

1h3h

–30

0

6h 5h

+60

+30

3h 0h

–10

–30

12h

–60

–3012h15h 0

+30

0h22h

S

S

S

S

S

TAURUS, ARIESBest visible: December – January

CETUSBest visible:

November – January

PEGASUSBest visible:

October – November

LUPUS, CENTAURUS, CRUXBest visible:April – August

PERSEUS, ANDROMEDABest visible: December

VELA, CARINA, PUPPISBest visible: January – May

CORVUS, CRATERBest visible:

March – June

CANCER, GEMINIBest visible:

January – March

CANIS MINOR, ORION,CANIS MAJOR, LEPUSBest visible: January – March

E C L I P T I C

E C L I P T I C

E C L I P T I C

Aldebaran

Pleiades

Betelgeuse

Algol

Rigil Kentaurus

Hadar

Mimosa

SCORPIUS

LIBRAHYDRA

VELA

AQUARIUS

PISCES

ANDROMEDA

CARINA

TAURUS

PISCES

PEGASUS

ARIES

PERSEUSANDROMEDA

PERSEUS

ANDROMEDA

PISCES

CETUS

ORION

GEMINI

TAURUS

ARIES

CANISMAJOR

CRUX

CENTAURUS

VELA

PUPPIS

CARINA

VIRGO

HYDRA

HYDRA

HYDRA

CRATER

CORVUS

TAURUS

PUPPIS

PISCES

CANIS MINOR

ORION

TAURUSLEO

HYDRA

ARIES

ORION

CANIS MINOR

CANISMAJOR

LEPUSCETUS

GEMINI

CANCER

LUPUS

CENTAURUSPEGASUS

CRUXAcrux

Canopus

Acrux

Adhara

–60

–30

12h

9 h

6 h

S

S

SS

Pollux

Castor

Procyon

Betelgeuse

Procyon

Rigel

Sirius

Mira

Adhara

AQUARIUS

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5

–20

+20

14h

12h

0

+30

12h 10h

S

S

LEOBest visible:March – May

AQUARIUSBest visible:

September – November

PISCESBest visible:

October – December

PISCIS AUSTRINUS, GRUSBest visible:

August – December

VIRGOBest visible:April – June

BOOTESBest visible:May – July

Arcturus

Arcturus

Spica

Regulus

VIRGO

CANCER

HYDRA

LEOBOOTES

LIBRA VIRGO

VIRGO

LUPUS

OPHIUCHUS

SCORPIUS

LIBRA

CORVUS

GRUS

PISCIS AUSTRINUS

PISCESAQUARIUS

CRATER

HYDRA

–30

+10

18h

16 h

S

OPHIUCHUS, SERPENSBest visible:

June – August

CAPRICORNUS, SAGITTARIUSBest visible:

July – OctoberSERPENSCAUDA

SERPENSCAPUT

OPHIUCHUS

LEO

VIRGO

BOOTES

CAPRICORNUS

SAGITTARIUS

SCORPIUS

LEOCANCER

VIRGO

CENTAURUS

AQUARIUS

AQUARIUS

ARIES

CETUS

PISCES

CAPRICORNUS

PISCIS AUSTRINUS

PEGASUS

ANDROMEDA

AQUARIUS

SCORPIUSSAGITTARIUS

SAGITTARIUS

–10

–40

21h

18 h

+20

+50

14h16h

S

S

S

0

–30

12h 9h

S

HYDRA ( + Corvus, Crater)Best visible:March – May

SCORPIUS, LIBRABest visible: May – August

0

0

–30

–30

–50

+30

23h

23h

21h

21h

23h2h

–10

–40

15h18h

S

S

S

Fomalhaut

Fomalhaut

Antares

Regulus

Spica

E C L I P T I C

E C L I P T I C

E C L I P T I C

E C L I P T I C

E C L I P T I C

E C L I P T I C

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The stars by nameThe night sky is a friendly place. You can greet many of the stars by name. At least 100 of the brighter stars have proper names, mostly Greek, Latin or (par tic u larly) Arabic in origin. For example, Fomalhaut means ‘the mouth of the fish’, and Rigel means ‘the foot’ (of Orion). Antares means ‘the rival of Ares’, because its red colour is similar to that of the planet Ares (now called Mars). Regulus in Leo the Lion means ‘little king’ and Deneb is ‘the tail’ of Cygnus the Swan. It is fitting that Sirius, the bright est of the night­sky stars, has a name meaning ‘the spark ling one’. Many of these names have become very garbled over the cen tu ries and their origins are hard to find.

Astronomers do not use these names much, espe cially as only the brighter stars have them. Instead they follow a prac tice popu lar ised in the early seven teenth century by the German astron o mer Johann Bayer, though the system dates back to Ptolemy. They attach the letters of the Greek alpha bet (alpha, beta, gamma, delta, epsilon, and so on) to the stars in a con stel­la tion in general order of bright ness. After the letter comes the name of the con stel la tion in the pos ses sive (or gen i tive) form. When the Greek letters run out (which does not take long in most con stel la tions) ordi nary Roman letters are used.

For example, Antares (which marks the heart in the strik­ing con stel la tion of Scorpius the Scorpion) is offi cially Alpha Scorpii. Rigel, Betelgeuse and Bellatrix in Orion the Hunter are respec tively Alpha, Beta and Gamma Orionis. Regulus is Alpha Leonis and so on. The bright est star in a con stel la tion is usually called alpha, but this is not always the case. For example, Pollux in Gemini the Twins is brighter than his brother Castor but is ranked as Beta Geminorum. The discrepancy is some times due to stars varying in bright­ness over the years, as with Betelgeuse in Orion, which is now notice ably fainter than Rigel.

The two ‘pointers’ that indi cate the way to the Southern Cross are known both as Rigil Kentaurus (‘the foot of the Centaur’) and Hadar (for ‘ground’) and as Alpha and Beta Centauri, being the bright est stars in the con stel la tion of Centaurus the Centaur. The Southern Cross itself is known as Crux Australis. Its five main stars in order clock wise, begin­ning at the bottom, are Alpha Crucis (also called Acrux), Beta Crucis (Mimosa), Gamma Crucis (at the top), Delta Crucis and Epsilon Crucis.

TheGreekalphabet

alpha nu beta xı gamma omicron delta pı epsılon rho zeta sigma eta tau theta upsılon iota phı kappa chı lambda psı mu omega

Another naming system was begun by English Astronomer Royal John Flamsteed in 1725. This numbers the stars in a con stel la tion by posi tion, usually by increas ing right ascen­sion (see page 12), for example, 61 Cygni. Brighter stars will have several names. Betelgeuse is 58 Orionis as well as Alpha Orionis. There are other naming systems for var i able stars and for double stars, usually based on various cat a logues.

Brighter and fainter starsNot all the stars look the same. They differ, not only in their posi tions in the sky, but also in their colours and bright nesses. The bright ness of a star is indi cated by its mag ni tude, making use of a system going back nearly 2000 years to the Greek astron o mer Ptolemy. He divided the bright nesses of the naked­eye stars into six levels, with the bright est stars being of the first mag ni tude. Those stars are roughly two and a half times brighter than the more numer ous second mag ni tude stars, which are in turn two and a half times brighter than the even more plen ti ful third mag ni tude stars. This means that a first mag ni tude star is six times brighter than a third mag ni­tude star, and 100 times brighter than a sixth mag ni tude star, the faint est visible without aid.

Nowadays this system had been extended. Magnitudes can be sub di vided, so that 2.3 is just fainter than 2.2, and just brighter than 2.4. First mag ni tude stars are those brighter than 1.5 (there are 21 of these), second mag ni tude objects are brighter than 2.5, and so on. Originally, the bright ness of stars was judged by the expe ri enced eye; modern instru ments assess bright ness to one hun dredth of a mag ni tude.

Very bright objects have neg a tive mag ni tudes, such as the Sun (minus 27), the Moon (minus 12), some planets (for example, Venus can reach minus 4) and even some of the bright est stars (for example, Sirius is now offi cially listed as mag ni tude minus 1.5). The system works for fainter stars as well, with the faint est stars detect able with the largest tele­scopes being of mag ni tude 27. (That makes them more than 10 billion times fainter than Alpha Centauri, the brighter of the two point ers to the Southern Cross!)

How far away are the stars?To be precise, what we have dis cussed so far is a star’s appar­ent mag ni tude, that is, how bright it seems to be from Earth. That depends not only on how bright a star actu ally is but also on how far away it is. For example, the two Pointers (Alpha and Beta Centauri) look to be about equal in bright ness. But Beta is in fact 10,000 times brighter than Alpha and 100 times further away.

The common measure of dis tance in deep space is the light year. This is the dis tance travelled by a ray of light (cov­er ing 300,000 km every second) in a year, and is equal to roughly 10 tril lion (10 million million) kilo me tres. The nearest bright star to us (other than the Sun) is Alpha Centauri, the brighter of the two Pointers to the Southern Cross. This is a little over 4 light years away. Sirius is 9 light years distant, Canopus 74 light years, Spica 220 light years,

6

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Antares 520 light years. About 25 stars lie within 12 light years of the Sun.

The most distant first mag ni tude stars, such as Rigel in the con stel la tion of Orion the Hunter or Deneb in Cygnus the Swan, are 1400 or 1500 light years away. To be seen so clearly at such a dis tance they must be immensely bright, much brighter in reality than our Sun. The measure of intrin sic bright ness is abso lute mag ni tude, which means how bright the star would appear to be if it was 33 light years away. Our Sun has an abso lute mag ni tude of 4.8, while Rigel rates at 8.1. The dif fer ence of 13 mag ni tudes makes Rigel 60,000 times brighter than the Sun in reality. If Rigel were as close as Alpha Centauri, it would out shine the Moon.

The varying dis tances to the stars have another impli ca tion. It means that the various star pat terns as we see them from Earth are often purely a matter of chance and depend on our viewing point. From else where in our stellar neigh bour hood, the Southern Cross may not look like a cross at all. Nor are the pat terns eter nally endur ing. The seem ingly ‘fixed’ stars are actu ally hur ry ing through space at many kilo me tres per second. Even their great dis tances from us will not hide that move ment if we are willing to wait a few thou sand years.

Stars of many colours Across the sky, we find stars of many colours. Green and purple stars may be rare but many stars have a red, orange or yellow tinge, or a hint or more of blue. Nowadays, we under­stand that colour indi cates how hot the surface of the star is. Stars cooler than our Sun are redder in colour (for example, Aldebaran in Taurus the Bull, or Gamma Crucis), and stars hotter than our Sun are bluer in colour (for example, Sirius or Beta Centauri).

We also now know the link between a star’s colour and its intrin sic bright ness. For at least 90 per cent of stars, the brighter they are, the hotter (and there fore bluer) they are. Such stars are also bigger and heavier than the dimmer, cooler, redder stars. They also have shorter lives. Our Sun has been shining for over 5 billion years and has some billions of years of life left yet. In contrast, very large, hot, blue stars exhaust their fuel in only a few million years. Most of the stars redder than the Sun (and there fore smaller than it) are too dim to be seen with the unaided eye.

There are excep tions. A class of stars known as giants are both brighter and redder (or at least yel lower) than our Sun. This is even truer for the super giants. Both Betelgeuse and

7

Table 2. The 25 brightest stars

Name Constellation Apparentmag. Distance(l.y.) Absolutemag.

Sirius Canis Major 1.46 8.6 1.4Canopus Carina 0.72 74. 2.5Rigil Kentaurus Centaurus 0.27 4.3 4.1Arcturus Bootes 0.04 34. 0.2Vega Lyra 0.03 25. 0.6Capella Auriga 0.08 41. 0.4Rigel Orion 0.12 1400. 8.1Procyon Canis Minor 0.38 11.4 2.6Achernar Eridanus 0.46 69. 1.3Betelgeuse Orion 0.50 (var) 1400. 7.2Hadar Centaurus 0.61 (var) 320. 4.4Acrux Crux 0.76 510. 4.6Altair Aquila 0.77 16. 2.3Aldebaran Taurus 0.85 (var) 60. 0.3Antares Scorpius 0.96 (var) 520. 5.2Spica Virgo 0.98 (var) 220. 3.2Pollux Gemini 1.14 40. 0.7Fomalhaut Piscis Austrinus 1.16 22. 2.0Becrux (Mimosa) Crux 1.25 (var) 460. 4.7Deneb Cygnus 1.25 1500. 7.2Regulus Leo 1.35 69. 0.3Adhara Canis Major 1.50 570. 4.8Castor Gemini 1.57 49. 0.5Gacrux Crux 1.63 (var) 120. 1.2Shaula Scorpius 1.63 (var) 320. 3.5

Note: var variable.

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Antares are cool and red (at 3000 degrees their surface tem­per a tures are half that of the Sun) but they are vast in size and bright ness, 10,000 times or more the bright ness of the Sun and perhaps 500 times its diam e ter. Placed where the Sun is they would engulf the inner planets, includ ing Mars. These behe moths are stars in old age.

Another group of stars, the white dwarfs, are both hot and dim. They are also small and rep re sent the remains of once much brighter and bigger stars. Their inner fires have gone out.

Sizes and distances in the skyIt is useful early on to find a simple way to indi cate the appar­ent dis tances between stars in the sky and the sizes of the con stel la tions. The usual measure is in degrees with 90 degrees from the horizon to the zenith (the highest point in the sky, directly over head) and 90 degrees between the four main points in the compass (say from north to east).

Your hands are a good rough guide to dis tances. The hand spread out at arm’s length meas ures about 20 degrees from the tip of the thumb to the tip of the little finger. Across the clenched fist (includ ing the thumb) totals about 10 degrees at arm’s length. A fist plus a span makes up 30 degrees, the size of many a large con stel la tion, such as Leo or Orion or Scorpius. For smaller sep ar a tions, use the thumb (about 2 degrees) or the little finger (about 1 degree), again at arm’s length.

It is easy to over es ti mate the sizes of objects in the night sky. The Moon, for example, is only half a degree across, and is easily covered by the little finger at arm’s length. Its appar­ently larger size near the horizon is an illu sion, as use of the little finger will quickly show.

For small dis tances, we break down each degree into 60 minutes (of arc) and each minute into 60 seconds. The Moon is there fore about 30 minutes or 1800 seconds of arc across. We need these small meas ures to describe, for example, the sep ar a tions of double stars (page 8), which are usually meas ured in seconds of arc, or the sizes of nebulae (pages 18–19), which usually amount to some tens of minutes of arc. Minutes of arc are denoted by the symbol , seconds by .

More than one at a timeMost stars have some addi tional point of inter est. For instance many are multi ple stars, two or more stars revolv ing about a common centre. Of the 25 stars within 12 light years of our Sun, 17 belong to double or even triple star systems. Our Sun, having no com pan ion, is in the minor ity.

Alpha Centauri, the nearest star to the Sun, is a triple. Two of its com po nent stars are close and similar, being both Sun­like. The third, a dim red star called Proxima Centauri, is suf fi ciently far away from the other two to be notice ably closer to us. The most spec tac u lar multi ple stars are those in which the com po­nent stars are about equal in bright ness but dif fer ent in colour.

To the naked eye, nearly all these multi ples appear to be single stars, but in many cases binoc u lars or a small tele scope can dis tin guish the sep ar ate stars. The closer together the stars are the larger the tele scope needed to sep ar ate them.

Under ideal con di tions, a pair of good binoc u lars with 50 mm lenses will be able to sep ar ate a pair of sixth mag ni­tude stars only two and a half seconds of arc apart (a second of arc is about 2000th of the appar ent angular diam e ter of the Moon). A tele scope of 120 mm aper ture will sep ar ate a pair only 1 arc second apart. The stars are harder to split if they are unequal in bright ness, or if they are much fainter or brighter than the sixth mag ni tude.

There are some notable naked­eye doubles, such as Theta Tauri and Epsilon Lyrae. The latter is a good test of keen sight, while each com po nent is itself double, with a small tele scope needed to resolve them.

Various astron o mers have assem bled cat a logues of multi­ple stars. Three drawn on in this book are those of Dunlop (sig nified by a Greek delta), Struve (Sigma) and Herschel (h). The Dunlop list con tains many south ern stars.

Stars that changeOther stars provide fas ci na tion by varying in bright ness, by a little or a lot, reg u larly or unpre dict ably. About 3 per cent of all naked­eye stars are var i ables. You can tell a var i able star from its name. The letters R to Z are put in front of the name of the con stel la tion, and if more names are needed, the system uses the pre fixes RR to RZ, SS to SZ and so on. For example, RR Lyrae is a var i able star (and a famous type of var i able star at that).

These var i able stars are of several types.About 20 per cent of var i able stars are eclips ing var i­

ables. These are double stars so aligned that one of the pair passes first in front of and then behind the other. The way the bright ness of the com bined light of the two stars varies depends on their rel a tive bright nesses. If one is very much brighter than the other, there will be one deep minimum in the ‘light curve’ (when the dim star hides the bright one) and one shallow maximum (when the bright star is in front).

This is the case with the most famous such star, the ‘demon star’ Algol (Beta Persei). This varies in mag ni tude from 2.2 to 3.5 every three days. In the case of Beta Lyrae, the stars are more even in bright ness and the light varies more grad u ally over the whole period.

Far more common (more than 60 per cent of all var i ables) are single stars that pulsate in some way, mostly in and out. For such pul sat ing var i ables, the amount of change and the time taken cover a wide range and have a range of causes.

For Mira­type stars (of which Omicron Ceti, the ‘won der­ful star’ is the proto type), a typical range of mag ni tudes is 4 to 11 (that is, from a naked­eye object to one invis ible even in binoc u lars), with the vari a tions taking any thing from 80 to 1000 days. Mira­type stars are red giants or super giants and make up one fifth of all var i ables.

For Cepheids (of which Delta Cephei is the proto type), bright ness will swing by two mag ni tudes in between one and 135 days. Though quite rare (less than 1 per cent of all var i­ables) Cepheids are of par tic u lar inter est, since the time taken for the swing is directly related to the star’s abso lute bright­ness. This has let astron o mers use them as ‘stan dard candles’ to plot dis tances in the uni verse. Cepheids are super giant blue

8

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and white stars, which appear to inflate and deflate in size by about 10 per cent. RR Lyrae stars are similar to Cepheids, but the vari a tions take two days at most.

Flare stars or novae sud denly increase in bright ness by a factor of a thou sand or more, and then fade away once more into obscur ity. Many other stars are irreg u lar var i ables or semi­reg u lar at best. Betelgeuse is an example. That makes their swings hard if not impos sible to predict and there fore more impor tant to track. Amateur astron o mers can play a sig nifi cant role here.

The heavens in motionThe heavens do not stand still. Throughout the night, the posi­tions of the stars change rel a tive to the horizon and the zenith, though not rel a tive to each other (that is, the con stel la tions hold their shapes). Generally speak ing, stars first appear some­where along the eastern horizon and slowly move west wards across the sky. They are highest in the sky when cross ing the median, that is, the line north and south passing right over­head (through the zenith). Some hours later, the stars in ques­tion will set at some point on the western horizon.

Even 10 minutes of observ ing, using your hands to mark the posi tion of a bright star rel a tive to some nearby object such as a tree or build ing, will show that the stars are on the move. Since the heavens turn over roughly once a day, the stars shift by some 15 degrees every hour. That is about one and a half fist widths at arm’s length. This grand motion, like so many in the night sky, is only appar ent, since it is actu ally the Earth that is turning from west to east.

For stars high in the south ern sky, the turning of the earth shows as a steady clock wise move ment of the stars around a fixed point known as the south celes tial pole (‘south pole’ for short). This point lies due south and at an angle above the horizon equal to the observer’s lat i tude. For an observer at 35 degrees south lat i tude, the pole lies 35 degrees above the south ern horizon. For observ ers further north, it is lower in the sky, for those further south, it is higher.

The south ern stars appear to circle the pole at the same 15 degrees per hour rate, amount ing to a 90 degree or right angle shift every six hours. This means that, if a star such as Achernar lies due east of the pole at six in the evening, it would be above the pole at mid night and due west of it at six in the morning.

The north celes tial pole, visible to people in Europe, North America and North Asia but below the horizon for us, is marked by a bright ish star called Polaris (or the Pole Star), which marks the end of the tail of the con stel la tion of the Little Bear (Ursa Minor). There is no southern ‘pole star’. The nearest star to the South Pole (Sigma Octantis) is quite faint (as its name would suggest), but the pole is quite easy to find using some of the nearby bright stars.

A line extended through the long bar of the Southern Cross passes very close to the Pole, which lies some four cross­lengths (about 27 degrees) from Acrux. A line passing at right angles between the Pointers also finds the Pole. So the Pole lies where the two lines (through the Cross, between the

Pointers) intersect. A point on the horizon directly below the Pole marks due south. Skywatchers have no excuse for being lost if the south ern stars are visible.

Mapping the sky

To help us get to know the night sky better, skywatch ers have been making maps and charts of the heavens for thou sands of years, just as explor ers and geog ra phers have done with the surface of the Earth we live on. The map on pages 10–11 is an example. It shows the whole sky in four pieces, with the brighter stars (down to mag ni tude 3) and the boun dar ies of the 88 con stel la tions marked. The numbers in boxes refer to Sky Charts 1 to 20 in the third part of this book, which show the night sky in much greater detail.

The Earth is a sphere (more or less) and the con ti nents and seas lie on its surface (more or less). The stars are very dif fer­ent. They lie at vastly varying dis tances from us, and we can map them only by ima gin ing that they are attached to the inside of a vast ‘celestial sphere’ (size unknown) centred on the Earth (Indeed, until a few hundred years ago, most people thought that really was the case!).

Trying to make maps on flat­plane paper of the inside of this celes tial sphere meets the problem faced by car tog ra phers on Earth. The job cannot be done without dis tort ing the picture, espe cially away from the equator. Some maps show Greenland bigger than Australia, which is not the case. We have kept the dis tor tion down by drawing sep ar ate maps for the regions of sky around the north and south celes tial poles.

One aspect of the maps is puz zling. With north at the bottom of the map, and south at the top, the right­hand end should mark the west. On a map of the Earth that would cer­tainly be true. Instead, the right­hand end indi cates the east. The dif fer ence arises from the fact a map of the surface of the Earth is drawn from the outside looking in. Sky maps are drawn from the inside of the celes tial sphere looking out. This reverses some of the direc tions.

The line around the middleIf Map A were a map of the Earth, the line across the middle of the rec tan gu lar chart (marked 0 degrees) would be the equator. On this map it marks the celes tial equator, an imag­i nary line across the night sky, 90 degrees from each of the celes tial poles (that is, running around the widest part of the celes tial sphere).

Where the celes tial equator lies in the sky depends on where you are. For observ ers on the Earth’s equator, it passes right over head from east to west. If you were at the south (geo graphic) pole, it would lie along the horizon, with the south celes tial pole right overhead.

Throughout the south ern hemi sphere, the celes tial equator still cuts the horizon due east and west, but passes across the north ern sky, missing the zenith by an amount equal to the observer’s lat i tude. Thus for an observer at 35 degrees south

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lat i tude, the celes tial equator crosses the north ern sky 35 degrees away from the zenith, or 55 degrees above the north ern horizon. Some notable stars, such as the ‘belt stars’ of Orion (see Sky Chart 6) or those of Virgo (Sky Chart 9), lie very close to the celes tial equator, and can there fore show you where it can be found.

The dotted line on the map, curved so that it is some times north and some times south of the celes tial equator, is the eclip tic, which marks the annual path of the Sun against the back ground of the stars. The eclip tic cuts the equator in two places, known as the equi noxes, and reaches its maximum dis tances north and south of the equator (231⁄2 degrees) at two other points, known as the sols tices. Along the way, the eclip tic passes through 12 con stel la tions, pop u larly called the Signs of the Zodiac. See pages 12–13 for more on these impor tant matters.

Also shown curving north and south of the equator (but going much further north and south than the eclip tic does) is a broad and patchy band of light with the popular name of the Milky Way. See page 18 for more on this.

The grid of the sky: (a) declinationOn maps of the Earth, we find our way around by using the grid of lines marking lat i tude and lon gi tude. The same is true with maps of the sky, with a few dif fer ences. Distance north and south of the celes tial equator, the equiv a lent of lat i tude on Earth, is known as dec li na tion (dec. for short) and increases from zero degrees on the equator to 90 degrees at the poles. We do not speak of north or south in describ ing dec li na tion. Instead, dec li na tion north of the celes tial equator is listed as pos i tive, dec li na tion south is neg a tive. On most of the star maps in this book, lines of dec li na tion are spaced 10 degrees apart.

Declination tells a lot about how the stars appear in the night sky. Stars lying close to the celes tial equator (such as the Belt Stars of Orion or some of the stars of Virgo) always rise and set due east and west and are above the horizon for around 12 hours at a stretch. Stars north of the equator (that is, with pos i tive dec li na tions) rise north of east, set north of west and are visible for less than 12 hours from rising to setting. Arcturus, Vega or the stars of Gemini are exam ples.

The further north the stars (the more pos i tive their dec li­na tion) the lower they are in the sky (even when cross ing the merid ian) and the briefer their appear ances. The most north erly stars will not rise at all when viewed from south of the equator. Your lat i tude sets the limit. From our popular viewing spot at 35 degrees south, stars with more than plus 55 degrees dec li na tion are always out of sight. These include famous north ern con stel la tions such as the Big and Little Bears.

Stars south of the equator (that is, with neg a tive dec li na­tions) rise south of east, set south of west and are above the horizon for at least 12 hours at a time. Fomalhaut, Canopus or the stars of Scorpius dem on strate this. The further south a star lies (that is, the more neg a tive its dec li na tion) the longer

it stays in view. Many never set. From 35 degrees south lati­tude, stars south of minus 55 degrees dec li na tion are always in view (if the sky is clear). So we can always see the Southern Cross and the Pointers, though you will find them in dif fer ent parts of the sky depend ing on the time of the night and the year.

The grid of the sky: (b) right ascensionThe celes tial equiv a lent of lon gi tude, the posi tion of an object east or west of a fixed point, is right ascen sion (RA for short). There are some major dif fer ences from ter res trial lon gi tude. Right ascen sion is meas ured in hours, not degrees, though each hour is equiv a lent to 15 degrees. Unlike lon gi tude, which is meas ured both east and west, right ascen sion increases in only one direc tion, that is, to the east, running from zero hours to 24 hours in one circuit of the sky.

The start ing point for the meas ure ment of lon gi tude (zero degrees) on Earth is the Greenwich Observatory in London. On the celes tial sphere the meas ure ment of right ascen sion starts where the eclip tic cuts the celes tial equator near the western end of the con stel la tion of Pisces the Fish (one of the signs of the zodiac: see page 13). This point is called the vernal equinox. During its yearly migra tion along the eclip tic, the Sun reaches this point around 21 March, which is the start of spring in the Northern Hemisphere.

A line north and south across the sky passing through the vernal equinox there fore marks zero hours of right ascen sion. Similar lines through the other equinox and the two sol tices mark 12, 6 and 18 hours of right ascen sion. On Map A and on most maps in this book RA is marked every hour.

At any time only half the total sky area shown on the map will be visible, the sector cov er ing six hours of right ascen sion either side of the stars then cross ing the merid ian. The dates at the bottom of Map A indi cate the month of the year when the stars on each line of right ascen sion will be on or close to the merid ian (that is, highest in the sky) at nine in the evening.

Sun and Moon

Dominating the sky by day and night are the two bright est extra­terrestrial objects, the Sun and the Moon. Their move­ments deter mine how much of the rest of the uni verse we are per mit ted to see. For instance, the stars are not fully visible until the rota tion of the Earth has taken the Sun a suit able dis­tance (some 18 degrees) below the horizon and the sky has grown dark. At lat i tudes around 35 degrees, this point in time (known as the end of astro nom i cal twi light) is not reached until more than an hour after sunset.

The ecliptic and the zodiacThe Sun also appar ently con trols which stars and con stel la­tions will become visible once it sets. While the stars behind the Sun will not be visible in its glare, you can figure out

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where the Sun is among the stars by looking at the stars that rise just before the Sun rises, or set just after it sets. The yearly journey of the Earth around the Sun causes the Sun, as seen from Earth, to move against the back ground of the stars, tracing out the eclip tic.

Astronomers long ago divided the stars along this path into 12 con stel la tions, and each of these is now assigned a stretch of sky 30 degrees long. The number of these special constel­lations equals the number of months in the year, and they make up the 12 signs of the zodiac, which means ‘the proces­sion of the animals’. All but one of these con stel la tions rep re­sent living things. In the order they are usually given, they are: Aries the Ram, Taurus the Bull, Gemini the Twins, Cancer the Crab, Leo the Lion, Virgo the Young Maiden, Libra the Scales, Scorpius the Scorpion, Sagittarius the Archer, Capricornus the Sea­Goat, Aquarius the Water­Carrier, Pisces the Fish.

The Sun takes a month to pass through each zodiac con­stel la tion, and during that month the Sun is said to be ‘in’ that con stel la tion. In this regard, a slow shift is evident in the machin ery of the cosmos, known as the pre ces sion of the equi noxes. Nowadays, the Sun is among the western stars of Pisces around March 21 at the start of the north ern spring. But 2000 years ago this impor tant date was marked by the Sun moving into Aries, one sign to the east. The astrol o gers and casters of horo scopes still allo cate the sign of Aries to the month begin ning 21 March.

Nowadays, the summer sol stice (Midsummer’s Day) north of the equator arrives when the Sun enters Gemini. But 2000 years ago, the sol stice lay in Cancer (hence the now out dated term Tropic of Cancer). Two thou sand years earlier still, at the height of Babylonian astron omy (and astrol ogy), the sol stice was hosted by Leo. This is a likely origin of the asso ci a tion between the lion and royalty (for more on this see the text to Sky Chart 16).

Sky change throughout the yearThe move ment of the Sun along the eclip tic places it about 1 degree further east rel a tive to the sur round ing stars each day. Conversely, the stars are about 1 degree further west rel a tive to the Sun every day. Since the posi tion of the Sun con trols our reck on ing of time (traditionally, noon or twelve midday on the clock marks the time when the Sun is highest in the sky), this shift causes the stars to rise and set earlier each day (accord­ing to the clock) by about four minutes. This difference gives rise to the concept of ‘sidereal time’. That is, time according to the stars rather than to the Sun. You can explore this in more detail on pages 21–22.

The net result of all this is a slow change in the appear ance of the night sky through out the year, on top of the faster change which occurs hourly through out the night. From week to week, new stars and con stel la tions are found rising in the east as the Sun goes down while those near the western horizon are stead ily swal lowed up by the sunset.

Four minutes a day makes two hours a month and six hours in three months. So stars which are rising in the east at sunset in January will be cross ing over head at sunset in April. In July they

will be setting with the Sun and will not be visible again in the night sky for a few months, and then only in the ‘small hours’.

This move ment also affects stars high in the south ern sky, stars that never set. At a given time each evening, those stars will be found posi tioned about 1 degree further clock wise. One degree a day amounts to 90 degrees in three months. So the Southern Cross, which is high in the south­east in the early evening in May, will be high in the south­west three months later. In November it will be low in the south­west (and almost upside­down), while an early February evening will find it low in the south­east but rising.

The moving MoonThe move ments of the Moon, and the changes in its appear­ance, are the most obvious of all the night sky hap pen ings. For this reason many ancient cal en dars were based on the Moon; the Hebrew and Islamic cal en dars still are, with each month (‘moonth’) begin ning with the very first appear ance of the Moon as a thin cres cent after sunset. The move ment of the Moon among the stars of the zodiac is the result of its orbit of the Earth from west to east (the same direc tion as the Earth turns on its own axis).

The monthly cycle beings with the Moon invis ible against the glare of the Sun (the strict meaning of the term New Moon). Within a day or two it appears as a thin cres cent (what is com monly called ‘a new moon’) close to the western horizon after sunset. As the days go by, the Moon moves stead ily east among the stars, along a line lying close to the eclip tic. Each night it is posi tioned about 12 degrees (a little more than a fist width at arm’s length) further east, taking about two and a half days to pass through each zodiac sign.

At the same time, its rising occurs about 50 minutes earlier each day, amount ing to a change of 24 hours in the full month, and its appear ance alters as it passes through its cycle of phases. Since one side of the Moon is fully lit at any time, the chang ing phase of the Moon is the result of a chang ing rela tion ship in space between the Moon, the Sun and the Earth. This rela tion­ship, driven mostly by the Moon’s monthly orbit of the Earth, permits us to see a chang ing amount of the lit face.

The cycle of phases begins at New Moon when the Moon is on the sunward side of the Earth and we can see only the side in dark ness. Day by day, the Moon moves further away from the Sun in the sky, and its cres cent broad ens (a waxing cres cent). Worth looking for on a very young Moon is the effect of earth shine. Light reflected by the Earth onto the unlit portion causes it to glow faintly (‘the Old Moon in the Young Moon’s arms’). More than a few days after New Moon this sight is lost in the growing glare of the sunlit portion

After seven days, the Moon reaches First Quarter, with the left­hand half of its face lit, rising at noon and setting at mid­night. Another seven days as a waxing gibbous moon brings it to Full Moon, rising as the Sun sets and setting as it rises. The Moon then lies oppo site the Sun in the sky, and its lit face is fully visible.

Thereafter the gibbous moon wanes, reach ing Last Quarter after another seven days. The right­hand side is lit and Moonrise

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occurs at mid night. Seven more days as a waning cres cent brings another New Moon. Just before it becomes new, the Moon is visible as a thin cres cent low in the eastern sky before dawn.

The major impact of the Moon on night sky viewing comes from the light it sheds, which can dom i nate the light of the stars. Fainter sights such as the Milky Way are lost in its glare. The best time to view the stars is when the Moon is absent or merely a thin cres cent. For early evening sky watch­ing, that means the period from a few days after Full Moon through until a day or two after New Moon.

EclipsesFrom time to time as the Moon orbits the Earth, it passes through our shadow. Such an eclipse of the Moon (or lunar eclipse) can occur only at Full Moon, though at most Full Moons there is no eclipse, as the Moon passes above or below the cone of shadow the Earth casts into space. If the eclipse is total (that is, the Moon passes through the centre of the Earth’s cone of shadow), the Moon darkens to a strik ing coppery­red colour. Superstitious people in ancient times referred to the Moon ‘turning to blood’. On other occa sions, only some of the Moon will be blacked out. Lunar eclip ses can be seen from wherever the Moon is above the horizon at the time of the eclipse, which nor mally lasts several hours.

The equiv a lent pos sibil ity at New Moon is for an eclipse of the Sun (or solar eclipse) with the Moon passing directly in front of the Sun and cutting off its light for a few minutes. Since these are obvi ously daytime events, they do not concern us here, other than to say that during a total solar eclipse, the sky does darken enough for the stars to appear. In any one year, up to half a dozen eclip ses of the Sun and the Moon will occur, though few if any will be total.

The face of the MoonEven with the naked eye, the mottled face of the Moon is inter est ing. The view through binoc u lars or a small tele scope turns the inter est into fas ci na tion. The most obvious mark ings are large dark areas called by the ancients the mare or ‘seas’, for so they thought them to be. We now know them to be vast almost smooth plains of vol canic rock, but the old names persist. A fertile imag i na tion can turn them into the fea tures of the face of the ‘man in the Moon’ or into other images (such as a rabbit) in other cul tures.

Though smaller, some of the craters and moun tain ranges are strik ing, espe cially when close to the ter mi na tor, the line divid ing the lit and unlit por tions of the Moon. Along this line, an observer on the Moon would see the Sun rising or setting, and the low Sun casts long shadows, greatly enhanc­ing the relief. The high lands are very old; the craters formed more recently by the impact of aster oids or comets.

Because the Moon spins on its axis in the same time inter­val as it orbits the Earth, it always keeps the same face turned towards us. From Earth we cannot see most of the ‘far side’ of the Moon. However, space craft have sent back images of the hidden side, showing it to be much like the face we see

though with many fewer mare. It is not correct to call the far side the ‘dark side’, since through out the month, it receives as much light as the side we see.

Map B iden tifies the main mark ings on the Moon’s surface, as revealed at Full Moon. The craters carry mostly the names of famous people, such as ancient and modern astronomers or other scientists, or philosophers. The largest of the craters are a hundred kilometres or more across. The diagram is oriented as the Moon is when seen high in the north ern sky with the naked eye or with binoc u lars (that is, the North Pole of the Moon is at the bottom). If the Moon is rising, turn the chart clock wise (so that north is on the left). If the Moon is setting, turn it anti­clockwise. If you are using a tele scope (which inverts the view), turn the chart upside down.

The planets

From time to time, you will notice among the stars other points of light that do not hold their posi tions as the regular stars do, and which are there fore not marked on any star map. The ancient Greek astron o mers called these ‘planetos’ or ‘wan der ing stars’, from which comes our word planet. Five of these were known in ancient times (Mercury, Venus, Mars, Jupiter and Saturn), and two more (Uranus and Neptune) have since been found using the tele scope. Pluto, discovered in 1930, was long regarded as the ninth planet but recently lost that status.

The ancients were puzzled by these objects and their often strange beha vi our. They thought they were living things, even man i fes ta tions of the Gods, and named them accord ingly. We now know that planets are cold, rocky or gaseous spheres in orbit around the Sun, as is our Earth. Two of the planets (Mercury and Venus) are closer to the Sun than we are and orbit it more quickly (the inner planets); the others lie outside the Earth’s orbit and travel more slowly (the outer planets).

Some are larger than the Earth, some smaller. Like the Moon, they shine only by the reflected light of the Sun, unlike the true stars which make their own light. A planet’s bright­ness is a measure of its size (Jupiter is bright because it is big), its near ness (Venus is bright because it is close) or the nature of its surface (Venus again because it is covered with highly reflec tive cloud).

The movements of the outer planetsGenerally speak ing, these planets behave as do the Sun and the Moon. They appear to move east wards along paths that lie close to the eclip tic, passing through the zodiac con stel la tions one by one. Mars moves most quickly, taking just over two years to com plete one circuit of the sky and spend ing two months in each zodiac con stel la tion. Jupiter, with a 12­year journey around the eclip tic, takes a year to pass through one sign. The others travel more slowly still, with Saturn spend ing two and a half years, Uranus seven years and Neptune 14 years.

This simple picture is com pli cated by retrograd ing. Over a period of some months in every year a planet ceases its usual

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east erly motion (that is, it becomes sta tion ary), moves back­wards (that is, towards the west), stops again (becomes sta tion ary a second time) and then resumes its east ward course. The further away a planet is, the longer retrograd ing lasts, but the smaller the dif fer ence it makes to the posi tion of the planet. For Mars, retrograd ing lasts only two months, but the out er most planets spend half the year moving back wards. However, Mars swings through a couple of constellations as it retrogrades, while Saturn rarely leaves the constellation it was in when it became stationary.

This odd beha vi our is only appar ent, not actual. In reality, the planets move stead ily onwards in their orbits at an almost

steady pace. Retrograding is due to the fact that the Earth, moving more quickly in its orbit than the planets outside it, over takes them ‘on the inside lane’, so that for a time they appear to move back wards. You see the same thing when out driving. As you pass another car, it appears to move back wards rel a tive to the scenery.

Roughly halfway through its move back wards, the planet reaches a point exactly oppo site the Sun in the sky (that is, it comes to oppo si tion). At oppo si tion, the planet rises around six in the evening and crosses the merid ian at mid night. The outer planets are bright est and appear largest in a tele scope at oppo si tion, as they are then closest to the Earth, though the

15

Map B. The main features of the surface of the Moon

MARETRANQUILITATIS

MAREHUMORUM

MARECRISIUM

MAREVAPORUM

SINUSAESTUUM

MARE FRIGORIS

SINUSIRIDUM SINUS

RORIS

OCEANISPROCELLARUM

MARESERENITATIS

OCEANIS IMBRIUM

Blancanus

VALLISRHEITA

MARENECTARIS

MAREFECUNDITATIS

MARENUBIUM

MARECOGNITUM

MONTESRIPHAEUS

MONTES

ALPESVALLIS ALPES

VALLISSCHRÖTERI

ScheinerClavius

SchillerPhocylidus

Schickard

Longomontanus

Tycho

Wilhelm

Wurzelbauer

Cuvier

Faraday

Maurolycus

FabriciusWalter

Werner

Regiomontanus

Purbach

Apianus

Playfair

G

Arzachel

Alpetragius

Alphonsus

Ptolemaeus

HerschelHipparchus

Albategnius

Abulfeda

TacitusCatharina

Sacrobosco

FracastoriusSantbechPetavius

Colombo

Vendelinus

Langrenus

Goclenius

Gutenberg Capella

Isidorus

Vlacq

Pitiscus

Fabricius

Metius

Rheita

Furnerius

Stevinus

Rabbi Levi

Piccolomini

SnelliusZugat

Stöfler

Gauricus

Cichus

PitatusMercator

Capuanus

Campanus Vieta

Mersenius

GassendiBullialdus

Aliacensis

Mädler

Geminus

Franklin

Cepheus

Hercules

Bürg

Endymion

Strabo

Atlas

Posidonius

Reinhold

Copernicus

Condorcet

ProciusPlinius

Vitruvius

Macrobius

Cleomedes

Burckhardt

Ritter Godin

AgrippaTriesnecker

Lansberg

CyrillusTheophilus

Delambre

Apollonius

FirmicusTarantius

Maskelyne

Julius Ceasar

Sabine

Messala

Bianchini

Mairan

Struve

SeleucusHerodotus

Aristarchus

LambertEuler

EratosthenesManilius

Menelaus

Harpalus

Crüger

Grimaldi

Riccioli

Kepler

Marius

Wallace

Timocharis

ArchimedesAutolycus

Aristillus

Cassini

Pico

Plato

Eudoxus

Aristoteles

W. Bond

RUPES ALTA

I

M.JU

RA

MONTES A

PENNINES

MONTES CARPATES

S

E W

N

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vari a tion is more notice able with Mars than with the more distant planets.

About six or seven months after oppo si tion, the planet dis­ap pears behind the Sun for a while and cannot be seen (that is, it reaches con junc tion with the Sun). Before con junc tion, the planet will be an evening star (that is, visible above the western horizon after sunset). After con junc tion, the planet becomes a morning star (visible in the east before dawn).

The movements of the inner planetsThe move ments of Mercury and Venus against the back ground of the stars are com pli cated by the fact that they never get very far away from the Sun (Mercury a maximum of about 27 degrees, Venus a maximum of less than 50 degrees). These planets there fore never come to oppo si tion and are never visible in the mid night sky. They accom pany the Sun in its yearly journey through the zodiac, being some times ahead of the Sun in the sky (that is, with eastern elon ga tion), and some times lagging behind (that is, with western elongation).

The inner planets have two con junc tions with the Sun during each orbit, one at which the planet passes the Sun on the near side (infe rior con junc tion), the other with the planet passing the Sun on the side away from the Earth (super ior con junc tion). Between super ior con junc tion and infe rior con junc tion, the planet is an evening star. Between infe rior con junc tion and super ior con junc tion, it is a morning star.

Like the Moon, Mercury and Venus both show phases when viewed with tele scopes, moving from thin cres cent to full disc and back again during each orbit. This, com bined with great vari a tion in their dis tances from us, causes the inner planets to vary greatly in appar ent size and bright ness. Maximum bright ness occurs close to the time of maximum elon ga tion east or west.

Which planet?If you find a planet among the stars but are not sure which one it is, the appli ca tion of a few simple rules will sort the matter out

Mercury is never easy to find, since it stays close to the Sun and to the twi light, and is there fore rarely seen against a dark sky. The give away is its rapid move ment among the stars, shift ing its posi tion mark edly from night to night rel a tive to nearby stars. This is appro pri ate. The planet was named after the fleet­footed mes sen ger of the gods in ancient Roman legend, and returns to the same posi tion in the sky (say to maximum eastern elon ga tion, at which time it is highest in the sky at sunset) every three months.

Venus on the other hand is very hard to miss, espe cially as ‘the evening star’, blazing in the west high above the sunset. (Any planet can become an evening star, of course, but Venus is the acme.) Showings of Venus as an evening star are spaced about eight months apart. It rises up to three hours before the Sun and sets up to three hours after, and so can clear the

twi light. At maximum mag ni tude it out shines every thing other than the Sun and Moon, and can cast a shadow on a moon less night. Its naming, after the Roman goddess of love and beauty, seems most appro pri ate.

The dis tinc tive red or pink colour of Mars, the result of it being covered by desert, was likened by the ancients to a drop of blood and so it was named after the god of war. Unlike the redder stars (such as Antares) with which it may be com­pared, Mars moves among the stars, pushing east through one zodiac sign every two months. At oppo si tion, small tele scopes may glimpse it as a coloured disc, with perhaps smudgy dark mark ings and a touch of white at the poles.

Jupiter is the largest planet and can get quite bright, though not as bright as Venus. It is there fore easy to spot, espe­cially in con stel la tions with dimmer stars. Its colour is almost white, and its move ment is stately, as befits a planet named after the king of the Roman gods. It takes a year to pass from one zodiac sign to the next. In a small tele scope, Jupiter will show as a dis tinct disc, with perhaps some streaky mark ings.

Saturn moves the most slowly of the naked­eye planets, so sug gest ing a link to the Roman god of old age. It will be found within the con fines of a single zodiac con stel la tion for almost three years. It may be found any where along the eclip tic, and its off­white colour is an added source of iden tifi ca tion. The chief attrac tion of Saturn is its system of rings, which can be seen in small tele scopes.

There is a fas ci nat ing link between the planets and the old pseudo­science of alchemy, the fore run ner of modern chem is try. In ancient lore, each hea venly object was linked to one of the seven metals known at the time, and the same symbol used for both the metal and the planet. So Mercury was linked to the metal mercury, Venus to copper, Mars to iron (its rusty redness helped there), Jupiter to tin and Saturn to lead. The Sun (gold) and the Moon (silver) were also part of this scheme.

We can also con tem plate the way the names of the planets are imbed ded in our lan guage, such as in the days of the week (for example, Saturday was orig i nally Saturn’s Day), and in words like mer cu rial, vene real, martial, jovial (Jupiter was also called Jove) and sat ur nine.

The waltz of the planetsThe move ment of the various planets through the zodiac at dif fer ent speeds pro duces an endless variety of events, easily tracked with the naked eye. Among these are numer ous con­junc tions, with planets drawing close to each other (often within a few degrees), to bright stars (such as Regulus, Pollux, Spica and Antares, which lie close to the eclip tic) or to the Moon. Conjunctions with the Moon are most inter est ing when the Moon is a cres cent, and there fore not overly bright. At times three or even four planets will be found together in the same part of the sky, and their move ments from week to week or even night to night are fas ci nat ing to watch.

The Moon will some times occult a planet or star, that is, pass in front of it. It is inter est ing to watch for the dis ap pear­ance or re­emer gence of the object, again espe cially if the

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Moon is a cres cent. Details of con junc tions, occul ta tions and other events (such as eclip ses) can be found in pub li ca tions com piled by astro nom i cal soci eties (such a listing is called an ephem e ris) and on sale in astron omy supply shops.

You can also refer to Appendix B, which gives the posi tions of four of the five naked­eye planets each month for the next ten years, together with details of some sig nifi cant plan e tary events.

Satellites, comets, meteors, minor planetsThe solar system, the region of space con trolled by the gravity of the Sun, con tains much more than the planets. Many of these other objects are night­sky sights.

Satellites. All the planets except Mercury and Venus have ‘moons’ orbit ing them, though most of these are very faint when viewed from Earth (mag ni tude 10 or fainter). The easiest to pick out are the four largest sat el lites of Jupiter (Io, Europa, Ganymede and Callisto). With mag ni tudes at oppo­si tion between 4.6 and 5.7 these can be seen with the naked eye if con di tions are right, and are an easy target for binoc u­lars. They orbit Jupiter with periods of between one and a half and 17 days, pro duc ing a con stantly varying dis tri bu tion of bright points on either side of the planet. The pre dicted posi­tions of the moons are pro vided in an ephem e ris.

The moons of Jupiter line up on either side of the planet more often than you might expect. This is the result of the strong gravity of Jupiter locking the orbits of the three inner moons into a res o nance. Each time Ganymede com pletes one orbit, Europa goes round exactly twice and Io exactly four times.

Saturn’s bright est sat el lite, Titan (period 16 days), is within reach of binoc u lars at maximum mag ni tude, 8.3, with Rhea (period four and half days) also a pos sibil ity at maximum mag ni tude, 9.7.

Comets. Comets are icy bodies trav el ling around the Sun in long thin orbits, becom ing bright and devel op ing the char­ac ter is tic tail when near the Sun. A few become spec tac u lar naked­eye objects, but the arrival of those is unpre dict able. A bright comet may take thou sands of years to return if it comes back at all.

Of the reg u larly return ing comets, only the famous Halley’s Comet is bright enough to make a real showing to the naked eye, but a number of others are worth track ing down with binoc u lars. Again, you should refer to an ephem­e ris for details.

Meteor showers. As comets orbit the Sun, they leave behind a trail of dust and small frag ments. When the Earth passes through this trail, some of the rubble is swept up by gravity and burns up in the Earth’s atmos phere, appear ing as bright streaks of light across the sky. Such meteor showers (com­monly dubbed ‘falling stars’ or ‘shoot ing stars’) emerge from par tic u lar points in the night sky (their radi ants) at certain times of the year. A list of the main showers is given in Table 3, and ref er ence is made to them in the text beside the Sky Charts. At the times of year the various showers occur, the constellations hosting them do not rise until late, and so the showers can normally be seen only in the small hours.

Minor Planets. Often called aster oids, these are small rocky bodies orbit ing the Sun. There are most likely hun dreds of thou sands of them, but most are small, a few hundred kilo­me tres at most. Most lie between Mars and Jupiter in the aster oid belt. The largest, Ceres, is only 1000 km across. The bright est is Vesta, which can reach mag ni tude 5.2 and so be a naked­eye sight on a clear dark night. More are visible with binoc u lars or a small tele scope, and the loca tions of the bright est among the stars are given in an ephem e ris.

A variety of sights

The night sky has more to offer than indi vid ual stars and planets. Many other sights may be glimpsed with the naked eye, but all benefit from the use of binoc u lars or a small tele­scope (you will do even better with a large tele scope!).

Stars get togetherIn many areas of the sky, the stars cluster together, often pro­vid ing a contrast with their varied colours. Some of these are open clus ters, with ample space between rel a tively small

17

Table 3. Main meteor showers

Peakrate(average) Normallimits Maximum perhour Radiant(RA/Dec)

Quarantids (in Bootes) Jan. 1–6 Jan. 3 60 15 hr 30 min/50Lyrids Apr. 19–25 Apr. 22 10 18 hr 10 min/32Eta Aquarids May 1–10 May 6 35 22 hr 20 min/01Delta Aquarids July 15 – Aug. 15 July 29 20 22 hr 39 min/17Perseids July 23 – Aug. 20 Aug. 12 75 3 hr 08 min/58Orionids Oct. 16–27 Oct. 22 25 6 hr 27 min/15Taurids Oct. 20 – Nov. 30 Nov. 5 10 3 hr 47 min/14Leonids Nov. 15–20 Nov. 17 10 10 hr 11 min/22Geminids Dec. 7–15 Dec. 13 75 7 hr 31 min/32

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numbers of stars. Such clus ters, which are com monly only 10 or 20 light years across at most, contain from as few as 10 stars to as many as 500, all orig i nally formed together from the one gas cloud. The Pleiades or ‘Seven Sisters’ in Taurus (there are actu ally more than 30 stars in this cluster), Praesepe or ‘the Beehive’ in Cancer, and the Jewel Box, hard by the Southern Cross, are all notable exam ples, but this book will refer you to dozens of others.

Far more thickly packed with stars are the glob u lar clus­ters, with up to a million stars crowd ing together like bees around a honey pot. These clus ters are huge balls of stars, tens or even hundreds of light years across, and the stars within are on average about a light year apart. Globular clus ters are in general both very old (con tain ing some of the most ancient stars known) and very remote (many lying 10,000 or 15,000 light years distant). Omega Centauri (again close to the Southern Cross) and 47 Tucanae near the Small Magellanic Cloud are among the finest such clus ters in the sky. We should add that even through a telescope it is not easy to appreciate the true form of a globular cluster; most of them look like fuzzy stars.

The Milky WayThe Milky Way, best seen on a clear dark night, appears as a faint band of light, winding its way around the sky and passing through or close by a number of con stel la tions, includ ing Crux, Vela, Carina, Canis Major, Orion, Auriga, Perseus, Cygnus, Aquila, Sagittarius and Scorpius. Ancient observ ers thought it was a stream of milk from the breast of some sky goddess and used the term galaxy from the Greek for ‘milk’.

Since the time of Galileo (though some Greeks 2000 years before guessed at the truth) we have known it is in fact made up of bil lions of stars, so distant and so closely clus tered together that the unaided eye cannot sep ar ate them. Binoculars or a tele scope will quickly reveal many of those stars. The Milky Way is widest and most dense between Scorpius and Sagittarius, where the most distant observ able stars are about 30,000 light years away.

The appear ance of the Milky Way is the con se quence of the Sun and its planets being located within a vast wheel­shaped con gre ga tion of stars, now known as the Milky Way galaxy (or simply ‘the galaxy’). The hub of this system lies beyond the stars of Scorpius and Sagittarius, and the rest of the Milky Way is simply the con se quence of looking across the galaxy along its longest dimen sion. Modern reck on ing makes our galaxy about 100,000 light years in diam e ter, about 10,000 light years thick in the centre, and about 3000 light years thick out in the outer suburbs where we are (some 30,000 light years from the hub). It con tains at least 200 thou sand million stars, 10 per cent of which are similar in size and tem per a ture to our Sun.

The axis of the ‘wheel’ of our galaxy can be taken to cut the celes tial sphere at the North Galactic Pole (NGP) and South Galactic Pole (SGP) (just as the Earth’s axis cuts it at the North and South Celestial Poles). The NGP lies in Coma Berenices, the SGP in Sculptor. The Sun and its planets lie

slightly above the plane of the Milky Way, so we see more stars (and more bright stars) looking south than looking north. That is one reason why the skies of the Southern Hemisphere are so bril liant!

Nebulae, dark and brightHere and there along its length, the Milky Way is divided by dark lanes and broken by patches appar ently devoid of stars, for example, in the Scorpius/Sagittarius region and in Cygnus. In truth, vast clouds of dust hanging in space block the light from the stars of the Milky Way in these regions. Other such dark nebulae (‘nebula’ is Latin for ‘a cloud’) include the Coal Sack beside the Southern Cross and the spec tac u lar but elusive (for small tele scopes anyway) Horsehead Nebula in Orion.

There are also a great many bright nebulae, patches and wisps of glowing gas. Some of these are ‘star nurseries’, patches of gas glowing pink from the energy of newly born stars within them. The Great Nebula in Orion is one such star nursery, as are the Trifid and Lagoon Nebulae front ing the Milky Way near Sagittarius. Indeed, emis sion nebulae of this kind are mostly found along the Milky Way, espe cially looking towards the galac tic centre.

Some nebulae asso ciated with young stars are blue rather than pink. This is the result of blue light from the young hot stars being scat tered by clouds of dust. The blue wisps of gas sur round ing the 50­million­year­old Pleiades form such a reflec tion nebula.

A warning about the colours. You will see them in photo­graphs but, alas, not with your eye directly (even with binoc­u lars). At low light levels, the human eye picks up little colour, and most of the nebulae will appear white with a green ish tinge. They are still worth seeking out.

A few nebulae mark the loca tions of stars in old age, ‘red giant’ stars which have shed their outer layers to form glowing rings of gas, some times mis lead ingly called plan e tary nebulae (they have nothing to do with planets). The Ring Nebula in Lyra the Harp is an example.

Others are ‘star cemeteries’, each marking the spot where very large stars at the end of their brief violent lives have blown them selves to pieces as super no vas. The Vela Nebula and the Crab Nebula in Taurus lie in that cat e gory, though both are hard to resolve into anything meaningful other than in large telescopes. The Crab Nebula is the remnant of the super nova recorded by Chinese astron o mers in 1054 AD.

Nebulae beyondStill other nebulae are vastly larger and more distant, since we now know that they are com plete star systems (gal ax ies) lying beyond our own. The two Clouds of Magellan, which appear as faint patches of light in the south ern sky, are the nearest of these, being some 200,000 light years away. They are rel a­tively small and are essen tially ‘satellites’ of our own Milky Way galaxy. Binoculars will reveal the strik ing Tarantula Nebula in the Large Magellanic Cloud, letting you glimpse the spidery outline that provoked the name.

18

S_Sky_Guide_TEXT_3ed_01.indd 18 7/5/08 11:30:48 AM

The Andromeda Galaxy, a naked­eye object in the north ern sky, is the nearest of the large exter nal gal ax ies, being two million light years distant. Such ‘island universes’, each con­tain ing bil lions of stars, are thickly clus tered in certain areas of the sky, most notably in the con stel la tions of Virgo, Coma Berenices and Canes Venatici. Numbers of gal ax ies are also found in Fornax, Sculptor, Leo and Perseus. These con stel la­tions lie close to the Galactic Poles. Galaxies are not found near the Milky Way as the dust clouds and thickly clus tered stars hide them from view.

The various clus ters and nebulae have been cat a logued several times. The oldest such effort was by the eight eenth­

century French comet­hunter Charles Messier, who noted over 100 fuzzy objects likely to be con fused with comets. His list is still often used. The Crab Nebula is M1, the Lagoon Nebula M16, the Orion Nebula M42, Praesepe M44, the ‘Sombrero Hat’ galaxy M104. Most of the Messier objects are in the north ern part of the sky.

More recent and more com pre hen sive is the New General Catalogue (NGC) first com plied over a hundred years ago with thou sands of entries. Objects listed with an N followed by a number are from the NGC. Other letter–number combina­tions in this book indicate other catalogues.

19

S_Sky_Guide_TEXT_3ed_01.indd 19 7/5/08 11:30:48 AM

S_Sky_Guide_TEXT_3ed_01.indd 20 7/5/08 11:30:48 AM

Using the Skyviews

The fol low ing 24 Skyviews rep re sent the night sky at dif fer ent times of the year and dif fer ent times of the night. Since the stars on show in the night sky change noticably from hour to hour during the night and week to week through out the year, it is vital that you choose the right Skyview to use.

Each Skyview has been drawn to cor re spond with a certain side real time. Sidereal time is set by the stars, rather than by the posi tion of the Sun, as in ordi nary solar time. Whereas a solar day is the period between two noons, that is, between two pas sages of the Sun across the merid ian, a side real day is the time between two suc ces sive ‘tran sits’ of the vernal equinox, or indeed of any par tic u lar star.

Since the east erly motion of the Sun along the eclip tic causes the stars to rise earlier each day by about four minutes

21

the SkyviewS

table 4. Choosing the right Skyview (by hour and date of observation)

Localtime(h)*

Date 17 18 19 20 21 22 23 00 01 02 03 04 05 06

Jan. 5 0 1 2 3 4 5 6 7 8 9 10 11 12 13 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14Feb. 5 2 3 4 5 6 7 8 9 10 11 12 13 14 15 20 3 4 5 6 7 8 9 10 11 12 13 14 15 16Mar. 7 4 5 6 7 8 9 10 11 12 13 14 15 16 17 22 5 6 7 8 9 10 11 12 13 14 15 16 17 18Apr. 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 22 7 8 9 10 11 12 13 14 15 16 17 18 19 20May 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 9 10 11 12 13 14 15 16 17 18 19 20 21 22June 6 10 11 12 13 14 15 16 17 18 19 20 21 22 23 22 11 12 13 14 15 16 17 18 19 20 21 22 23 24July 7 12 13 14 15 16 17 18 19 20 21 22 23 24 1 22 13 14 15 16 17 18 19 20 21 22 23 24 1 2Aug. 6 14 15 16 17 18 19 20 21 22 23 24 1 2 3 22 15 16 17 18 19 20 21 22 23 24 1 2 3 4Sep. 6 16 17 18 19 20 21 22 23 24 1 2 3 4 5 21 17 18 19 20 21 22 23 24 1 2 3 4 5 6Oct. 6 18 19 20 21 22 23 24 1 2 3 4 5 6 7 21 19 20 21 22 23 24 1 2 3 4 5 6 7 8Nov. 6 20 21 22 23 24 1 2 3 4 5 6 7 8 9 21 21 22 23 24 1 2 3 4 5 6 7 8 9 10Dec. 6 22 23 24 1 2 3 4 5 6 7 8 9 10 11 21 23 24 1 2 3 4 5 6 7 8 9 10 11 12

* Subtract one hour from these times during periods of daylight saving.

by the clock, a side real day is shorter than a solar day by four minutes. Put another way, the sidereal clock runs faster than the solar clock, gaining four minutes a day. Over the year, the difference builds up to a whole day. A year contains 365¼ solar days but 366¼ sidereal days. Put another way, the side­real clock runs faster than the solar clock, gaining four minutes a day.

To work out the side real time cor re spond ing to your day and time of observ ing, and there fore deter mine which Skyview to use, you can refer to Table 4.

Or you can apply the fol low ing simple rule:

Work out your solar time on a 24­hour clock and add four minutes for each day (or two hours for each month) that has passed since last 21 September. (On 21 September the solar and side real clocks read the same time.)

S_Sky_Guide_TEXT_3ed_02.indd 21 7/5/08 11:31:33 AM

An example: to work out si dereal time at 6 pm on 15 April, convert 6 pm to a 24­hour clock, which gives 18 hours. Add 13 hours (two hours for each of the 6½ months since last 21 September). That totals 31 hours, or 7 hours when reduced by 24 hours. So side real time at 6 pm on 15 April is 0700 hours and there fore Skyview 7 is the one to use.

To make it easy to decide which Skyview is the right one to use in the early evening (a time you will often be looking at the night sky), each Skyview has a two­week period listed above it (for example, January: weeks one and two). This means that particular Skyview accurately displays the layout of the night sky at 9 pm (taking account of daylight saving if it is in operation) in the middle of the stated fortnight (and will be very close to right throughout the whole period). In other words, for each Skyview, the side real time given is reached at 9 pm (2100 hours) in the middle of the given period (either the seventh or twenty­first day of the month). The Skyview and cal cu la tion given above let you use the Skyviews at any time of the night.

The turning of the Earth causes the posi tions of the stars and other objects rel a tive to the horizon and the zenith to change sur pris ingly quickly and notice ably. You need to be ready to move on to the next Skyview after obser va tion for one hour.

Each Skyview shows the whole sky visible at the given side­real time. The outer rim rep re sents the horizon. The Skyview should be turned so that the direc tion in which you are looking is at the bottom. Therefore, if you are looking south, the Skyview should be turned upside­down.

The Skyviews are drawn for only one lat i tude, namely 35 degrees south. Most of the main pop u la tion centres in the

Southern Hemisphere lie close to this par allel of lat i tude. Observers well to the north or to the south of this lat i tude will notice some dif fer ences in the vis ibil ity of stars near the north ern and south ern hori zons.

Each Skyview has marked the South Pole of the sky (around which the sky appears to turn) and the prime merid ian, namely the line marking 12 hours of right ascen­sion. Also marked are the celes tial equator and the eclip tic, which passes through the stars of the 12 zodiac signs.

The other impor tant feature of these Skyviews is the numbers which occur in the centres of large areas of each. These refer the user to the more detailed Sky Charts later in this book, which contain stars of higher mag ni tudes, together with impor tant sights through binoc u lars such as double stars and nebulae.

Two expres sions are com monly used in the text adjoin ing each Skyview. One is ‘cross ing the meridian’. This means a move ment from the eastern to the western half of the sky. ‘The top of the sky’, used for south ern stars, also refers to cross ing the merid ian, that is, rising as high as pos sible above the South Pole of the sky.

Reference is also made to posi tions of stars rel a tive to the South Pole of the sky in terms of hourly read ings on an ordi­nary clock face. So ‘three o’clock’ means due west of the pole, and ‘nine o’clock’ means due east.

Remember that these Skyviews show only stars. Bright star­like objects not marked on these Skyviews will almost cer tainly be planets, espe cially if they lie close to the eclip tic. (See page 14.)

22

S_Sky_Guide_TEXT_3ed_02.indd 22 7/5/08 11:31:33 AM

23

Skyview 19 pm, November: weeks three and four

Sidereal time 0100

The grand summer pano rama is now unfold ing in the eastern sky. Orion the Hunter, with its bright stars blue­white Rigel and reddish Betelgeuse, is now clear of the horizon. Taurus the Bull, includ ing reddish Aldebaran and the Pleiades, lies in the north­east. In the south­east, Sirius, the bright est of the stars, has risen, marking the larger of the Hunter’s two dogs. A little higher in the south­east lies Canopus, second bright est of all stars. It lies in Carina, the keel of the ship Argo.

Of the other bright stars, Achernar in Eridanus is high in the south, and Fomalhaut in the Southern Fish even higher in the south­west. In the west Altair in Aquila the Eagle is setting.

The Great Square of Pegasus stands in the north­west. The zodiac signs visible stretch from Sagitarrius now setting in the south­west, through Capricornus, Aquarius, Pisces and Aries, to Taurus in the north­east.

1

2

3

4

5

6

7

11

12

13 1420

19

0h

12h

CHAMAELEON

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Hyade

s

Pleiades

MUSCA

CRUX

CENTAURUS

CENTAURUS

VELA

PUPP

IS

CARINA

VOLANS

PICTOR

MENSA

DORADORETICULUM

HYDRUS

HORO

LOG

IUM

TUCANA

CA

ELU

M

PHOENIX

CO

LUM

BA CA

NIS

MA

JORS

CU

TUM

TRIANGULUM

AUSTRALE

CIRCINUSNORMA

ARA

LUPUS

APUS

OCTANS

PAVO

INDU

S GRUS

PISC

IS

AU

STR

INU

SM

ICR

OS

CO

PIUM

TELESCOPIUM

SCORPIUS

SAGITTARIU

S

CA

PR

ICO

RN

US

CORO

NA

AUSTRALIS

LEP

US

OR

ION M

ON

OC

ER

OS

TAU

RUS

ERID

AN

US

FOR

NA

X

SCULPTOR

CETUS

PISCES

ANDROMEDA

PERSEUS

AURIGAARIES

TRIANGULUM

AQ

UILA

DELPH

INU

S

SA

GITTA

EQU

ULEU

S

LACERTA

PEGASUS

AQ

UA

RIU

S

CYGNUS

Mimosa

AcruxRigel Kent

Hadar

Canop

us

Sir

ius

Adh

ara

Achernar

Mira

Algol

Alde

bara

n

Rig

el

Bet

elge

use

Fomalhaut

Altair

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

S_Sky_Guide_TEXT_3ed_02.indd 23 7/5/08 11:31:34 AM

24

Skyview 29 pm, December: weeks one and two

Sidereal time 0200

The eastern sky con tains the great sights: Orion the Hunter marked by the ‘saucepan’ and the bright stars Betelgeuse and Rigel, and in the north­east Aldebaran and the Pleiades marking the eye and the shoul der of Taurus the Bull. In the east Procyon in the Little Dog has risen, joining Sirius and the stars of Canis Major now well up in the south­east.

Also in the south­east is Canopus in Carina, second bright est of the stars after Sirius. Achernar in Eridanus has crossed the top of the sky, and now lies slightly south­west. Further west and higher is Fomalhaut, the mouth of the Southern Fish.

In the north­west, the Great Square of Pegasus is heading for the horizon. Of the zodiac signs, Sagittarius is setting in the south­west and the first stars of Gemini are in view in the north­east. Between those con stel la tions, from west to east, lie Capricornus, Aquarius, Pisces, Aries and Taurus.

1

2

3

4

56

7

11

12

13 1420

12h

0h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

Hyades

Pleiades

MUSCA

CRUXCENTAURUS

CENTAURUS

VELA

PYX

IS

PUPP

IS

ANTL

IA

CARINA

VOLANS

PICT

OR

MENSA

DORA

DO

RETICULUM

HYDRUS

HOROLOGIU

M

TUCANA

CA

ELU

M

PHO

ENIX

CO

LUM

BA

CA

NIS

MA

JOR

CA

NIS

MIN

OR

TRIANGULUM

AUSTRALE

CIRCINUS

ARA

APUS

OCTANS

PAVO

INDUS

GRU

S

PIS

CIS

AU

ST

RIN

US

MICRO

SCOPIU

M

TELESCOPIUM

SCORPIUS

SAGITTARIU

S

CA

PRIC

OR

NU

S

CORO

NA

AU

STRALIS

LEP

US

OR

ION

MO

NO

CE

RO

S

TAURUS

ERID

ANU

SFORNAX

SC

ULP

TO

R

CETUS

PISCES

ANDROMEDA

PERSEUS

AURIGA

GEM

INI

ARIES

TRIANGULUM

AQ

UILA

EQU

ULEU

SPEGASUS

AQ

UA

RIU

S

Mimosa

Acrux

Rigel Kent

Hadar

Cano

pus

Sir

ius

Adh

ara

Achernar

Mira

Algol

Aldeb

aran

Rig

el

Bete

lgeu

se

Proc

yon

Fomalhaut

S_Sky_Guide_TEXT_3ed_02.indd 24 7/5/08 11:31:36 AM

25

Skyview 39 pm, December: weeks three and four

Sidereal time 0300

The long faint line of stars marking Eridanus the River, ending in Achernar, lies through the zenith. In the south­east, the stars of the Argo con stel la tions (Carina, Puppis and Vela) are return ing to prom i nence, with Canopus in Carina leading the way. The Cross and Pointers have pushed off from the south ern horizon.

The east and north­east are the domain of the hunter Orion, with his dis tinc tive belt and sword. His two dogs are fol low­ing him up the sky: the Lesser Dog with its bright star Procyon and, further south, the Greater Dog with daz zling Sirius. Ahead of Orion lies the bull Taurus, notable for the star cluster the Pleiades and the red star Aldebaran as the bull’s eye.

Below Orion, the stars of the zodiac sign Gemini con tinue to rise. The line of the zodiac then runs west wards and up the sky through Taurus, Aries, Pisces and Aquarius to Capricornus, setting south of west. In the north­west Pegasus moves closer to setting.

8

15

1

2

3

4

5 6

7

11

12

13 14

20

12h

0h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

Hyades

Pleiades

MUSCA

CRUX

CENTAURUS

CENTAURUS

VELA

PYX

IS

PUPP

IS

AN

TLIA

CARINA

VOLANS

PICTOR

MENSA

DORADO

RETICULUM

HYDRUS

HOROLOGIUM

TUCANA

CA

ELU

MPH

OEN

IX

CO

LUM

BA

CA

NIS

MA

JOR

HY

DR

A

CA

NC

ER

CA

NIS

MIN

OR

TRIANGULUM

AUSTRALE

CIRCINUS

ARA

APUS

OCTANS

PAVO

INDUS

GRUS

PISC

ISA

US

TRIN

US

MICRO

SCOPIU

M

TELESCOPIUM

SAGITTARIUS

CA

PRIC

OR

NU

S

CORONA

AUSTRALIS

LEPU

S

OR

ION

MO

NO

CE

RO

S

TAURUS

ERIDANUS

FORN

AX

SC

ULPTO

R

CETUS

PISCES

ANDROMEDA

PERSEUS

AURIGA

GEMIN

I

ARIES

TRIANGULUM

PEGA

SUS

AQ

UA

RIU

S

Mimosa

Acrux

Rigel Kent Hadar

Canop

us

Sir

ius

Adh

ara

Achernar

Mira

Algol

Capella

Aldebaran

Rige

l

Betelg

euse

Proc

yon

Fomalhaut

S_Sky_Guide_TEXT_3ed_02.indd 25 7/5/08 11:31:37 AM

26

Skyview 49 pm, January: weeks one and two

Sidereal time 0400

In the south ern sky, two bright stars are prom i nent: Achernar in Eridanus high in the south­west, and Canopus in Carina well up in the south­east. The Cross and the Pointers remain close to the south­eastern horizon, but are moving up. High up, Fomalhaut in the Southern Fish is heading west.

Looking north, Taurus the Bull is well placed, with the Pleiades and Aldebaran unmis tak able. The bril liant con stel la tion of Orion the Hunter is above Taurus and east wards. Below Taurus, the far north ern star Capella, in Auriga the Charioteer, is making a brief appear ance.

The Great Square of Pegasus is now setting in the north­west, but the Great and Little Dogs con tinue to rise in the north­east. There also the bright stars of Gemini the Twins, Castor and Pollux, are now in view.

The faint early stars of Cancer the Crab in the north­east mark the east ern most of the visible zodiac signs. Running upwards and westwards are five other zodiac con stel la tions, Gemini, Taurus, Aries, Pisces and Aquarius.

8

15

1

2

3

4

5

6

7

12

13 14

12h

0h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

Hyades

Pleiades

MUSCA

CRUXCENTAURUS

VELA

PYX

IS

PUPP

IS

AN

TLIA

CARINA

VOLANS

PICTOR

MENSA

DORADO

RETICULUM

HYDRUS

HOROLOGIUM

TUCANA

CAELUM

PHO

ENIX

CO

LUM

BA

CA

NIS

MA

JOR

HY

DR

A

HYDRA

SE

XTA

NS

CAN

CER

CAN

IS M

INO

R

TRIANGULUMAUSTRALE

CIRCINUSARA

APUS

OCTANS

PAVOINDUS

GRUS

PISC

ISA

US

TRIN

US

MICROSCOPIUM

SAGITTARIUS

CA

PRIC

OR

NU

S

LEPUS

ORION MO

NO

CERO

S

TAURUS

ERIDANUS

FOR

NA

X

SC

ULPTO

R

CETUS

PISCES

ANDROMEDA PERSEUS

AURIGA

GEMINI

ARIES

TRIANGULUM

PEGA

SUS

AQ

UA

RIU

S

Mimosa

Acrux

RigelKent

Hadar

Canop

us

Sir

ius

Ad

har

a

Achernar

Mira

Algol

Capella

Aldebaran

Rigel

Betelgeuse Proc

yon

Pollu

x

Castor

Fomalhaut

S_Sky_Guide_TEXT_3ed_02.indd 26 7/5/08 11:31:38 AM

27

Skyview 59 pm, January: weeks three and four

Sidereal time 0500

In the north, Orion is nearing the merid ian, with the bril liant blue­white Rigel in the lead. Taurus the Bull has passed the merid ian, and, low on the horizon, Capella shines almost due north. Pisces and Aries are heading for the western horizon, but in the east Orion’s dogs and the stars of Gemini the Twins are rising high.

The early stars of Leo the Lion are now rising, with Regulus prom i nent. The faint stars of Cancer fill the space between Leo and Gemini. Leo is there fore the east ern most of the visible zodiac signs, fol lowed by Cancer, Gemini, Taurus, Aries and Pisces.

Looking south, the stars of Vela, Puppis and Carina, once parts of the greater con stel la tion of Argo, are high in the south­east. Canopus is leading them up the sky. Behind the Argo stars come those of the Cross and Pointers, still low in the south­east. Achernar is drop ping down the upper south­western sky, and Fomalhaut is nearing the south­western horizon.

8

15

1

2

3

4

5

67

12

13 14

1612

h

0h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

Hyades

Pleiades

MUSCA

CRUX

CENTAURUS

VELA

PYX

IS

PU

PP

IS

AN

TLIA

CR

ATER

CARINA

VOLANS

PICTOR

MENSA

DORADO

RETICULUM

HYDRUS

HOROLOGIUM

TUCANA

CAELUM

PHO

ENIX

COLU

MBA

CA

NIS

MA

JOR

LEO

HY

DR

A

HYDRA

SE

XTA

NS

CANCER

CANIS M

INOR

TRIANGULUMAUSTRALE

CIRCINUSARA

APUS

OCTANS

PAVOINDUS

GRU

S

PISCISA

USTRIN

US

MICROSCOPIUM

LEPUS

ORION

MO

NO

CERO

S

TAURUS

ERIDANUS

FOR

NA

X

SC

ULPTO

R

CETU

S

PISCES

ANDROMEDA

PERSEUS

AURIGA

GEMINI

ARIES

TRIANGULUM

PEGA

SUS

AQ

UA

RIU

S

Mimosa

Acrux

Rigel Kent

Hadar

Canopus

Sirius

Adh

ara

Reg

ulus

Achernar

Mira

Algol

Aldebaran

Rigel

Betelgeuse

Proc

yon

Pollux

Castor

Fomalhaut

Capella

S_Sky_Guide_TEXT_3ed_02.indd 27 7/5/08 11:31:40 AM

28

Skyview 69 pm, February: weeks one and two

Sidereal time 0600

In the south ern sky, bright Canopus in Carina is nearing the merid ian, as is even brighter Sirius in Canis Major, which is nearly over head. The Cross is close to nine o’clock, with Achernar almost oppo site it at around two o’clock. Fomalhaut is setting in the south­west.

Looking north, the bril liance of Orion the Hunter cannot be missed, just west of the merid ian and high in the sky. Taurus lies below Orion and a little to the west, while further down again is Auriga the Charioteer with Capella not far above the horizon.

In the north­west Pisces and Aries are approach ing their setting. Stretched across the sky to the east of Taurus are the stars of Gemini the Twins (with Procyon in the Little Dog just above), faint Cancer and most of Leo the Lion, notably Regulus. Thus six zodiac signs can be seen, from just rising Leo in the east to soon­to­set Pisces in the west.

9

16

8

15

12

3

4

5

6 7

12

13

14

12h0 h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTI

C

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

Hyades

Pleiades

MUSCA

CRUX CENTAURUS

VELA

PY

XIS

PU

PP

IS

AN

TLIA

CR

ATE

R

CO

RV

US

CARINAVOLANS

PICTOR

MENSA

DORADO

RETICULUM

HYDRUS

HOROLOGIUM

TUCANA

CAELUM

PHO

ENIX

COLU

MBA

CAN

ISM

AJOR

LEO

HYD

RA

HYD

RA

SEX

TAN

S

LYNX

CANCER

CANIS MIN

OR

TRIANGULUMAUSTRALE

CIRCINUS

LUPUSARA

APUS

OCTANS

PAVOINDUS

GRUS

PISCIS

AUSTRINUS

LEPUS

ORION

MO

NO

CERO

S

TAURUS

ER

IDA

NU

S

FOR

NA

X

SCULPTO

R

CE

TU

S

PISC

ES

PERSEUSAURIGA

GEMINI

ARIES

TRIANGULUM

AQ

UA

RIU

S

Mimosa

Acrux

Rigel Kent

Hadar

Canopus

Sirius

Adh

ara

Regu

lus

Achernar

Mira

Algol

Aldebaran

Rigel

Betelgeuse Procy

on

Pollux

Castor

Fomalhaut

Capella

S_Sky_Guide_TEXT_3ed_02.indd 28 7/5/08 11:31:41 AM

29

Skyview 79 pm, February: weeks three and four

Sidereal time 0700

Looking south, Canopus has joined Achernar west of the merid ian. The stars of Carina, Puppis and Vela are nearing the top of the sky. They cover the large area of the sky once allot ted to the one con stel la tion Argo. The Cross is becom ing prom i nent in the south­east, with the Pointers fol low ing it up.

Gemini the Twins now lies across the merid ian, with Castor and Pollux just east of north. Higher up but still east of the merid ian is the lesser of Orion’s dogs, marked by the bright star Procyon. Orion himself, with the well­known ‘saucepan’ and the bright stars Rigel and Betelgeuse, is high in the north­west sky, along with the Great Dog Sirius marking its heart.

East of Gemini, one of the zodiac signs, lie the faint stars of Cancer the Crab, then the brighter stars of Leo the Lion, includ­ing Regulus, and lastly the early stars of Virgo, now rising due east. At the western end of the visible segment of the zodiac lie some of the stars of Pisces and Aries.

9

16

8

15

1

2

3

4

5

6

7

13

14

12h

0 h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

Hyades

Pleiades

MUSCA

CRUX

CENTA

URUS

VELA

PYX

ISPUPP

IS

AN

TLIA

CR

AT

ER

VIR

GO

CO

RV

USCARINA

VOLANS

PICTOR

MENSA

DORADO

RETICULUM

HYDRUS

HORO

LOG

IUM

TUCANA

CA

ELUM

PHOEN

IX

CO

LUM

BA

CANIS

MAJOR

LEO

LEO M

INOR

HYDRA

HYD

RA

SEX

TAN

S

LYNX

CANCER

URSA MAJOR

CANIS MINOR

TRIANGULUM AUSTRALE CIRCINUS LUPUS

NORMA

ARA

APUS

OCTANS

PAVO

INDUS

GRUS

LEPUS

ORION

MONOCEROS

TAURUS

ERID

AN

US

FOR

NA

X

SCULPTO

R

CE

TU

SPIS

CES

PERSEUSAURIGA

GEMINI

ARIES

Mimosa

Acrux

Rigel Kent

Hadar

Canopus

Sirius

Adhara

Regul

us

Spi

ca

Achernar

Mira

Aldebaran

Rigel

BetelgeuseProcyon

Pollux

Castor

Capella

S_Sky_Guide_TEXT_3ed_02.indd 29 7/5/08 11:31:42 AM

30

Skyview 89 pm, March: weeks one and two

Sidereal time 0800

The spec tac u lar Pleiades are about to set in the north­west, with the rest of Taurus the Bull fol low ing them down. After only a brief appear ance, the far north ern star Capella in Auriga the Charioteer is going down again west of north. Gemini the Twins lies just west of north, with the ‘little dog star’ Procyon higher up the sky.

Cancer the Crab and Leo the Lion are pushing through the north­eastern sky, and behind Leo, the next zodiac sign Virgo the Young Maiden is now well in view. Its bright star Spica lies above the eastern horizon.

The western and north­western sky still belongs to Orion and his twin dogs. Sirius, the true Dog Star, is well placed to show its bril liance. Almost due south of Sirius is Canopus, the nearest to it in bright ness. It stands at one o’clock and is begin ning its descent of the south­western sky. The Cross, coming up in the south­east, has reached ten o’clock, with the Pointers trail ing behind.

17

9

16

8

15

1

2

3

4

5

6

7

14

12h

0h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

Hyades

Pleiades

MUSCA

CRUX

CEN

TAU

RUS

VELA

PYX

IS

PUPPIS

AN

TLI

A

CR

ATE

R

VIR

GO

CO

RV

US

CARINA

VOLANS

PICTOR

MENSA

DORADO

RETICULUM

HYDRUS

HOROLOGIUM

TUCANA

CAELU

M

PHOENIX

CO

LUM

BA

CANISMAJOR

LEO

LEO MINOR

HYDRA

HY

DR

A

SEXTA

NS

COM

ABE

REN

ICES

LYNX

CANCER

URSA MAJOR

CANIS MINOR

TRIANGULUM AUSTRALE

CIRCINUS

LUPU

S

LIBR

A

NORMA

ARA

APUS

OCTANS

PAVO

INDUS

GRUS

LEP

US

ORION

MONOCEROS

TAURUS

ERID

AN

US

FORN

AX

SCULPTOR

CETU

S

PERSEUS

AURIGA

GEMINIMim

osa

Acrux

Rigel Kent

Hadar

Canopus

Sirius

Adhara

Regulus

Sp

ica

Achernar

Mira

Aldebaran

Rigel

Betelgeuse

Procyon

Pollux

Castor

Capella

S_Sky_Guide_TEXT_3ed_02.indd 30 7/5/08 11:31:44 AM

31

Skyview 99 pm, March: weeks three and four

Sidereal time 0900

In the north­west, Taurus the Bull is close to setting, with the Pleiades first to go. Higher up and a little to the south, Orion the Hunter and his two Dogs make a spec tac u lar vista as they head for the horizon.

In the north ern sky, Gemini the Twins, with Castor and Pollux, lies west of the merid ian, and Leo the Lion with Regulus is east of it. Cancer the Crab, devoid of bright stars, lies due north between them. The line of zodiac signs is com pleted by Virgo the Young Maiden, coming up in the north­east with its bright star Spica, and by Libra the Scales, just rising.

To the south, the Pointers, and their home con stel la tion of Centaurus, are pushing the Cross up the sky in the south­east. The stars of the old Argo, now in Vela, Carina and Puppis, are at the top of the sky, with the leading star Canopus, second bright est in the sky, now past one o’clock. The ‘false cross’, made up of two stars of Vela and two of Carina, is right on the merid ian.

10

17

9

16

8

1

2

3

4

5

6

7

14

15

12h

0h

NORTH

EA

ST

SOUTH

WE

ST EC

LIPT

IC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

Hyades

MUSCA

CRUX

CEN

TAU

RUS

VELA

PYXIS

PU

PP

ISAN

TLIA

CR

ATER

VIR

GO

BO

OTE

S

CO

RV

US

CARINA

VOLANS

PICTOR

MENSA

DORADO

RETICULUM

HYDRUSHOROLOGIUM

TUCANA

CAELU

M

PHOENIX

CO

LUM

BA

CAN

IS

MA

JOR

LEO

LEO MINOR

HYDRA

HY

DR

A

SEXTANSCOM

ABER

ENIC

ES

LYNX

CANCER

URSA MAJOR

CANISMINOR

TRIANGULUMAUSTRALE

CIRCINUS

LUPU

S

LIB

RA

SCO

RPIU

SNORMA

ARA

APUS

OCTANS

PAVO

INDUS

LEP

US

ORIO

NM

ONOCEROS

TAU

RU

S

ERID

AN

US

FORN

AX

AURIGA

GEMINI

MimosaAcru

x Rigel

Kent

Hadar

Canopus

Sirius

Ad

hara

Regulus

Sp

ica

Achernar

Aldebaran

Rigel

Betelgeuse

Procyon

PolluxCastor

S_Sky_Guide_TEXT_3ed_02.indd 31 7/5/08 11:31:45 AM

32

Skyview 109 pm, April: weeks one and two

Sidereal time 1000

Two new con stel la tions, both zodiac signs, have cleared the eastern horizon. A bright ish pair of stars marks the first, Libra the Scales. The second is far more spec tac u lar. Scorpius the Scorpion forms a hook of stars, with red Antares among the first to rise.

In the south­west, Achernar at the head of the river Eridanus is now well down, with the Cross and the Pointers in con se­quence high in the south­east. At the top of the sky and into the south­west lie the Argo con stel la tions of Carina, Puppis and Vela, well marked by the bril liance of Canopus.

Orion is now nearing the western horizon, with the stars of his two dogs higher up the sky. Leo the Lion lies in the middle of the north ern vista, with Regulus near the merid ian. Leo is flanked by Virgo in the north­east and Gemini going down in the west. With Taurus now set, Gemini is the west ern most of the zodiac signs, with the line then running east through faint Cancer, Leo, Virgo, Libra and newly risen Scorpius.

10

17

9

16

8

1

2

3

4

6

7

14

15

12h

0h

NORTH

EA

ST

SOUTH

WE

ST

ECLI

PTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

MUSCA

CRUX

CEN

TAU

RUS

VELA

PYX

IS

PUPPIS

ANTLIA

CRATER

VIRG

O

BOO

TES

CO

RV

US

CARINA

VOLANS

PICTOR

MENSADORADO

RETICULUM

HYDRUSHOROLOGIUM

TUCANA

CAELU

M

PHOENIX

COLU

MBA

CA

NIS

MA

JOR

LEO

LEO MINOR

HYDRA

HY

DR

A

SEXTANS

COMA

BERENICES

CANES VENATICI

LYNX

CANCER

URSA MAJOR

CANISMINOR

TRIANGULUMAUSTRALE

CIRCINUS

LUPU

S

LIB

RA

SE

RP

EN

SC

AP

UT

SCO

RPIU

S

NORMA

ARA

TELESCOPIUM

APUS

OCTANS

PAVO

INDUS

LEPUS

OR

ION

MO

NO

CEROS

TAU

RU

S

ERIDANU

SFORNAX

GEMINI

Mimosa

Acrux

Rigel Kent

Ant

ares

Hadar

Canopus

Sirius

Adhara

Regulus

Spi

ca

Arc

turu

s

Achernar

Rig

el

Betelgeuse

Procyon

PolluxCastor

S_Sky_Guide_TEXT_3ed_02.indd 32 7/5/08 11:31:46 AM

33

Skyview 119 pm, April: weeks three and four

Sidereal time 1100

Scorpius the Scorpion, with its red star Antares, rides clear of the eastern horizon. In the north­east orange Arcturus marks the posi tion of Bootes the Bearkeeper, while higher in the sky Spica glows in the hand of Virgo the Virgin.

Leo the Lion lies due north, with Regulus prom i nent. Gemini now in the north­west is the west ern most of the visible zodiac signs, with Cancer, Leo, Virgo, Libra and Scorpius lying suc ces sively further east.

The great con stel la tion Orion is setting, leaving the western sky dom i nated by the stars of the Great and Little Dogs, includ­ing Sirius and Procyon.

In the south ern sky, the stars of the Argo con stel la tions (Carina, Puppis and Vela) are heading down in the south­west, with Canopus leading the way. Achernar is almost out of sight. The Cross is nearing the top of the sky in the south­east with the stars of the Centaur grouped around. Below the Pointers, three stars form the dis tinc tive Southern Triangle.

18

10

17

9

16

8

1

2 3

4

6

7

15

SouthPole

12h

0h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

CHAMAELEON

MUSCA

CRUX

CEN

TAU

RU

SVELA

PY

XIS

PUPPIS

AN

TLIA

CRATER

VIRGO

BOO

TES

CORVUS

CARINA

VOLANSPICTOR

MENSADORADO

RETICULUM

HYDRUS

HOROLOGIUM

TUCANA

CAELUM

PHOENIX

COLU

MBA

CA

NIS

MA

JOR

LEO

LEO MINOR

HYDRA

HY

DR

A

SEXTANS

COMA

BERENICES

CANES VENATICILYNX

CANCER

URSA MAJOR

CANIS

MIN

OR

TRIANGULUMAUSTRALE

CIRCIN

US

LUPU

S

LIB

RA O

PH

IUC

HU

S

SER

PEN

SC

APU

TS

ERPE

NS

CA

UD

A

SCO

RPIU

S

SAG

ITTA

RIU

S

NORMA

ARA

TELESCOPIUM

CORONA

AUSTRALIS

APUS

OCTANS

PAVO

INDUS

LEPUS

OR

ION

MO

NO

CER

OS

ERIDANUS

GEMINI

Mimosa

AcruxRigel K

ent

Ant

ares

HadarCanopus

Siriu

s

Adhara

Regulus

Spi

ca

Arctu

rus

Achernar

Rigel

Betelgeuse Procyon

PolluxCastor

S_Sky_Guide_TEXT_3ed_02.indd 33 7/5/08 11:31:48 AM

34

Skyview 129 pm, May: weeks one and two

Sidereal time 1200

The unmis tak able hook of Scorpius, with red Antares in its centre, is climb ing the eastern sky, and the next zodiac sign, Sagittarius, looking more like a teapot than an archer, has risen in the south­east. The Cross is almost as high as it can get in the south, with the Pointers at ten o’clock. The bright star Canopus is almost at three o’clock in the south­west with the stars of the old Argo con stel la tions, Carina, Puppis and Vela, trail ing behind.

The new stars in the east are a ragged square belong ing to Ophiuchus, the Man Wrestling with a Serpent. Orange Arcturus in Bootes is prom i nent in the north­east, and Virgo is nearing the merid ian.

Leo the Lion now graces the north­west sky, with Regulus prom i nent, along with the faint stars of Cancer. Castor and Pollux, the bright stars of Gemini, are departing from view. Above the western horizon, the ‘dog stars’ Sirius and Procyon, both soon to set, remind us of the departed Orion.

11

18

10

17

9

16

8

1

2

3

4

6

7

15

12h

0h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

MUSCA

CRUX

CEN

TAU

RU

S

VELA

PYX

IS

PUPPIS

AN

TLIA

CRATER

VIRGO

BOOTES

CORVUS

CARINA

VOLANS

PICTOR

MENSADORADO

RETICULUM

HYDRUS

HOROLOGIUM

TUCANA

CAELUM

PHOENIX

COLU

MBA

CA

NIS

MA

JOR

LEO

LEO MINOR

HYD

RA

HY

DR

A

SEXTANS

COMA

BERENICES

CANES VENATICI

LYNX

CANCER

URSA MAJOR

URSA MAJOR

CA

NIS

MIN

OR

TRIANGULUMAUSTRALE

CIRCINUS

LUPU

S

LIB

RA

OP

HIU

CH

US

HER

CU

LES

CORONA

BOREALIS

SERP

ENS

CAPU

T

SER

PEN

S

CA

UD

A

SC

UTU

M

SCO

RPIU

S

SAG

ITTA

RIU

S

NO

RMA

ARA

TELESCOPIU

M

CORO

NA

AUST

RALI

S

APUS

OCTANS

PAVO

INDUS

LEPUS

OR

ION

MO

NO

CER

OS

ERIDANUS

ERIDANUS

GEM

INI

MimosaAcrux

Rigel Kent

Ant

ares

Hadar

Canopus

Siriu

s

Adhara

Regulus

Spica

Arcturus

Achernar

Procyon

Pollux

S_Sky_Guide_TEXT_3ed_02.indd 34 7/5/08 11:31:49 AM

35

Skyview 139 pm, May: weeks three and four

Sidereal time 1300

The sky due north is dom i nated by the zodiac sign Virgo with its bright star Spica. Leo the Lion with Regulus is heading for the horizon in the north­west. West of Leo lie the faint stars of Cancer the Crab. Ophiuchus the serpent man is clear of the north­eastern horizon, and another hero, Hercules, sim i larly large and faint, is rising further north.

To the south, the Cross is now just past the merid ian. Centaurus is high in the sky, and further east, the Scorpion is rising to prom i nence, with the teapot of Sagittarius the Archer close behind. The line of the zodiac runs north­west across the sky from Sagittarius, through Scorpius, Libra, Virgo and Leo, to the soon­to­set Cancer.

To the west, Canopus is sinking low. Both Sirius in the Great Dog and Procyon in the Little Dog float above the western horizon, ready to set in an hour or two.

11

18

10

17

9

16

8

12

3

4

7

15

12h

0h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

MUSCA

CRUX

CENTAURUS

VELA

PYX

IS

PUPPIS

AN

TLIA

CRATER

VIRGO

BOOTES

CORVUS

CARINA

VOLANS

PICTORMENSA

DORADO

RETICULUMHYDRUS

HOROLOGIUMTUCANA

GRUS

CAELUM

PHOENIX

COLUMBA

CAN

ISM

AJO

RLEO

LEO MINOR

HY

DR

A

HY

DR

A

SEXTA

NS

COMABERENICES

CANES VENATICI

LYNX

CAN

CER

URSA MAJOR

CA

NIS

MIN

OR

TRIANGULUM AUSTRALE

CIRCINUS

LUPU

S

LIBR

A

OPH

IUC

HU

S

HERCULESCORONA

BOREALIS

SERP

ENS

CAPU

T

SE

RP

EN

S

CA

UD

A SC

UTU

M

AQ

UIL

A

SC

OR

PIU

S

SAG

ITTA

RIU

S

NO

RMA

ARA TELESCOPIU

M

CORO

NA

AU

STRA

LIS

APUS

OCTANS

PAVO

INDUS

MO

NO

CE

RO

SAcrux

Rigel Kent

Ant

ares

Hadar

Canopus

Sirius

Adhara

Regulus

Spica

Arcturus

Achernar

Procyon

S_Sky_Guide_TEXT_3ed_02.indd 35 7/5/08 11:31:51 AM

36

Skyview 149 pm, June: weeks one and two

Sidereal time 1400

Most prom i nent in the north ern sky is Bootes the Herdsman, Ploughman or Bearkeeper, depend ing on which inter pre ta tion of legend is taken. Its leading star Arcturus is close to the merid ian. In the north­west, Leo the Lion is near to setting, with Regulus showing the way. Above Leo, Virgo is also heading down. Ophiuchus and Hercules hang in the north­east, big but dim.

The Pointers have reached the top of the south ern sky, pushing the Cross into the south­west. The stars of the Centaur lie in the zenith. As a result, Achernar is as low as it can get, hugging the south ern horizon.

Canopus in Carina, with the other old Argo stars, is well down in the south­west. Scorpius and Sagittarius stand high in the south­east, and below them the dimmer zodiac sign Capricornus the Sea­Goat is coming up.

19

11

18

10

17

9

16

8

1

2

3

4

7

12h

0h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

MUSCA

CRUX

CENTAU

RUS

VELAPYX

ISPU

PPIS

AN

TLIA

CR

ATER

VIRGO

BOOTES

CORVUS

CARINA

VOLANS

PICTOR

MENSA

DORADORETICULUM

HYDRUS

HOROLOGIUM

TUCANA

GRUS

PHOENIX

COLUMBA

CANIS

MAJO

R

LEO

LEO MINOR

HY

DR

A

HYDRA

SEX

TAN

S

COMABERENICES

CANES VENATICI

CA

NC

ER

URSA MAJOR

TRIANGULUM AUSTRALE

CIRCINUS

LUPU

S

LIBRA

OPH

IUCH

US

HERCULES

CORONA

BOREALIS

SERPENS

CAPUT

SER

PEN

SC

AU

DA

SC

UT

UM

AQ

UIL

A

SC

OR

PIU

S

SAG

ITTA

RIU

S

CA

PRIC

OR

NU

S

NORMA

ARA

TELE

SCOPIUM

MIC

ROSC

OPI

UM

CORO

NA

AU

STRA

LIS

APUS

OCTANS

PAVO

INDUS

MO

NO

CE

RO

SAcrux

MimosaRigelKent

An

tare

s

Hadar

Canopus

Adhara

Regulus

Spica

Arcturus

Achernar

S_Sky_Guide_TEXT_3ed_02.indd 36 7/5/08 11:31:52 AM

37

Skyview 159 pm, June: weeks three and four

Sidereal time 1500

The Cross, though high in the south­west, is now descend ing. The many stars of the old sign of Argo, now formed into the con stel la tions Vela, Puppis and Carina, crowd the south­west, with Canopus near the horizon. The bright ish Southern Triangle is about to cross the merid ian. In the east, Capricornus the Sea­Goat is all but up, so that six zodiac signs span the sky to the north­west where Leo is setting. The signs between (running east to west) are Sagittarius (the ‘teapot’), the bril liant Scorpius, the dimmer Libra and Virgo high in the north­west.

Filling the north ern sky are Bootes the Herdsman, with its bright star Arcturus well west of the merid ian, and, further east the heroes Hercules and Ophiuchus, large but with no bright stars. In the north­east, a new bright star has risen, Altair in Aquila the Eagle.

12

19

11

18

10

17

9

16

8

1

2

3

4

7

12h

0h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

MUSCA

CRUX

CENTA

URU

S

VELA

PYXIS

PUPPIS

AN

TLIA

CR

ATER

VIRGO

BOOTES

CORVU

S

CARINA

VOLANS

PICTOR

MENSA

DORADO

RETICULUM

HYDRUS

HOROLOGIUM

TUCANAGRUS

PHOENIX

LEO

HY

DR

A

HYDRA

SE

XTA

NS

COMABERENICES

CANES VENATICI

URSA MAJOR

URSA MAJOR

TRIANGULUMAUSTRALE

CIRCINUS

LUPUS

LIBRA

OPHIU

CHUS

LYRA

SA

GIT

TA

VULP

ECU

LA

HERCULES

CORONA

BOREALIS

SERPENSCAPUT

SERP

ENS

CAU

DA

SC

UTU

M

AQ

UIL

A

SC

OR

PIU

S

SA

GIT

TAR

IUS

CA

PR

ICO

RN

US A

QU

AR

IUS

NORMA

ARA

TELE

SCOPIUM

MIC

ROSC

OPI

UM

PISCIS

AUSTRINUS

CO

RO

NA

AU

STR

ALI

S

APUS

OCTANS

PAVO

INDUS

Acrux

Mimosa

RigelKent

Ant

ares

Alta

ir

Vega

Hadar

Canopus

Regulus

Spica

Arcturus

Achernar

S_Sky_Guide_TEXT_3ed_02.indd 37 7/5/08 11:31:53 AM

38

Skyview 169 pm, July: weeks one and two

Sidereal time 1600

In the north­east, Vega in Lyra the Harp has risen, making a pair with Altair in Aquila the Eagle higher in the east. In the north­west, Bootes with its bright star Arcturus vies with Virgo and Spica. Leo the Lion is setting, with Regulus already gone. Slightly east of north, a large area of sky is taken up with the less than spec tac u lar Hercules and Ophiuchus.

To the south, the Cross is now well past the merid ian and notice ably lower in the sky, stand ing at two o’clock. Anticlockwise from the Cross are the Pointers and the fainter Southern Triangle at the top of the sky.

Further north the strik ing Scorpius is almost over head, with other zodiac signs Sagittarius and Capricornus between it and the eastern horizon. Zodiac signs to the west are Libra, Virgo and the setting Leo.

Low in the south­east, two bright stars hug the horizon: the never­setting Achernar in Eridanus, and Fomalhaut in the Southern Fish.

12

19

11

18

10

17

9

16

8

1

2

3

4

0h

12h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

MUSCA

CRUX

CEN

TAU

RU

S

VELA

PYXIS

PUPPIS

AN

TLIAC

RA

TE

R

VIRGO

BOOTES

CO

RV

US

CARINA

VOLANS

PICTOR

MENSA

DORADO

RETICULUM

HYDRUS

HOROLOGIUM

TUCANA

GRUS

SCULPTO

R

PHOENIX

LEOH

YD

RA

HY

DR

A

SE

XTA

NS

COMABERENICES

CANES VENATICI

URSAMAJOR

TRIANGULUMAUSTRALE

CIRCINUS

LUPUS

LIBRA

OPHIUCHUS

LYRA

CYGNUSSA

GIT

TA DEL

PHIN

US

EQU

ULE

US

VULPECULA

HERCULES

CORONABOREALIS

SERPENSCAPUT

SERPENSCAUDA

SC

UTU

M

AQU

ILA

SC

OR

PIU

S

SA

GIT

TAR

IUS

CA

PRIC

OR

NU

S

AQ

UA

RIU

SNORMAARA

TELESCOPIU

M

MIC

RO

SC

OPI

UM

PISC

IS

AUST

RIN

US

CO

RO

NA

AU

STR

ALI

S

APUS

OCTANS

ERIDANUS

PAVO INDUS

Acrux

MimosaRigel Kent

Antare

s

Alta

ir

Vega

Hadar

Canopus

Spica

Arcturus

Achernar

Fom

alha

ut

S_Sky_Guide_TEXT_3ed_02.indd 38 7/5/08 11:31:55 AM

39

Skyview 179 pm, July: weeks three and four

Sidereal time 1700

The spec tac u lar Scorpius is now over head, lying across the Milky Way. Running down to the eastern horizon are three other zodiac signs, the teapot­like Sagittarius the Archer, faint tri an gu lar Capricornus the Sea­Goat, and newly rising Aquarius the Water­Carrier. To the west of Scorpius lie a pair of stars marking Libra the Scales, and Virgo close to setting.

In the south­east, the bright star Fomalhaut is prom i nent, marking the Southern Fish. In the south­west, the Cross and the Pointers are going down and the stars of the Argo con stel la tions (Carina and Vela) are drop ping out of sight. Puppis has already gone.

In the north­west, the bright star Spica in the setting con stel la tion Virgo is still well up, while further east lies Bootes with its lead star Arcturus. Due north lie the large but faint star signs of Ophiuchus and Hercules. In the north­east, we find Lyra the Harp with Vega and Altair, the bright est star in Aquila the Eagle.

20

12

19

11

18

10

17

9

8

1

2

3

4

0h

12h

NORTH

EA

ST

SOUTH

WE

ST ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

MUSCA

CRUX

CENTA

URU

S

VELA

ANTLIA

CR

ATER

VIR

GO

BOOTES

CO

RV

US

CARINAVOLANS

PICTOR

MENSA

DORADO

RETICULUM

HYDRUS

HOROLOGIUM

TUCANA

GRUS

SCU

LPTO

R

PHOENIX

LEO

HYD

RA

COM

A

BERENICES

TRIANGULUMAUSTRALE

CIRCINUS

LUPU

S

LIBRA

OPHIUCHUS

LYRA

CYGNUS

SAGITTA

DELP

HIN

US

EQU

ULE

US

PEG

AS

US

VULPECULA

HERCULES

DRACO

CORONABOREALIS

SERPENSCAPUT

SERPENS

CAUDA

SCU

TUM

AQUILA

SCORPIUS

SA

GIT

TAR

IUS

CA

PRIC

OR

NU

S

AQ

UA

RIU

S

NORMA

ARA

TELESCOPIUM

MIC

RO

SC

OPI

UM

PISC

IS

AUST

RIN

US

CO

RO

NA

AU

ST

RA

LIS

APUS

OCTANS

ERIDANUS

PAVO

INDU

S

Acrux

Mim

osa

Rigel Kent

AntaresAl

tair

Vega

Hadar

Spica

Arcturus

Achernar

Fom

alha

ut

S_Sky_Guide_TEXT_3ed_02.indd 39 7/5/08 11:31:56 AM

40

Skyview 189 pm, August: weeks one and two

Sidereal time 1800

In the north­east, a third bright star has risen, Deneb at the tail of Cygnus the Swan. With Vega in Lyra and Altair in Aquila, it makes up the prom i nent Winter Triangle, to be visible for some months. In the west, Virgo with its bright star Spica is prepar­ing to set and Arcturus in Bootes is close to setting. The large faint con stel la tions Ophiuchus and Hercules fill the sky just west of north.

Looking south, the Cross is now at three o’clock in the south­west and going down, with the Pointers and the dis tinc tive but only bright ish Southern Triangle above it.

Higher up still, six zodiac signs arch across the sky, from Aquarius in the north­east, through Capricornus and the bright well­placed Sagittarius and Scorpius, on through less showy Libra to Virgo setting in the west. Bright Fomalhaut in the Southern Fish lies almost due east of the Pole.

5

20

12

19

11

18

10

17

9

8

1

2

34

0h12 h

NORTH

EA

ST

SOUTH

WE

ST ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

MUSCA

CRUX

CENTA

URU

S

VELA

ANTLIA

CR

ATER

VIR

GO

BOOTES

CO

RV

US

CARINA

VOLANS

PICTOR

MENSA

DORADO

RETICULUM

HYDRUS

HOROLOGIUM

TUCANA

GRUS

SC

ULP

TOR

CET

US

PHOEN

IXHYDRA

COM

A

BERENICES

TRIANGULUM

AUSTRALECIRCINUS

LUPU

S

LIBR

A

OPHIUCHUS

LYRA

CYGNUS

SAGITTA

DELPHIN

US

EQU

ULE

US

PEG

ASU

S

PIS

CES

VULPECULA

HERCULES

DRACO

CORONABOREALIS

SERPENSCAPUT

SERPENS

CAUDA

SCUTUM

AQUILA

SC

OR

PIUS

SA

GIT

TAR

IUS

CA

PR

ICO

RN

US AQ

UA

RIU

S

NORMA

ARA

TELESCOPIUM

MIC

RO

SC

OPI

UM

PISC

IS

AU

STRI

NU

S

CO

RO

NA

AU

ST

RA

LIS

APUS

OCTANS

ERIDANUS

PAVO

INDUS

AcruxM

imosa

RigelKent

An

tares

Altair

Vega

Deneb

Hadar

Sp

icaArcturus

Achernar

Fom

alha

ut

S_Sky_Guide_TEXT_3ed_02.indd 40 7/5/08 11:31:57 AM

41

Skyview 199 pm, August: weeks three and four

Sidereal time 1900

The north ern sky is dom i nated by the three bright stars of the Winter Triangle, Vega in Lyra the Harp almost due north, Deneb in Cygnus the Swan a little to the east, and Altair in Aquila the Eagle high in the sky. The rest of the north is dull by com par i­son; Aquarius and the rising Pegasus in the north­east, the large but dim Ophiuchus and Hercules in the north­west, and Virgo and Bootes setting in the west and north­west.

The Cross is well down in the south­west, with the Pointers above it. Higher still, curved Scorpius is past the merid ian. Libra and Sagittarius, both zodiac signs, lie west and east respec tively of Scorpius. The west ern most sign is the setting Virgo, while Capricornus and Aquarius lie north­east of Sagittarius. The latter are out shone by Fomalhaut in the Southern Fish, which is now prom i nent in the south­east.

5

20

12

19

11

18

10

17

9

1

2

3

4

0h

12 h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEONMUSCA

CRUX

CENTAU

RUS

VELA

VIR

GO

BOOTES

CO

RV

US

CARINA

VOLANS

PICTOR

MENSA

DORADO

RETICULUM

HYDRUS

HOROLOGIUM

TUCANA

GRU

S

SC

ULP

TOR

CE

TU

S

PHO

ENIX

FORNAX

HYDRA

TRIANGULUM

AUSTRALE

CIRCINUS

LUPU

S

LIBR

A

OPHIUCHUS

LYRACYGNUS

SAGITTADELPHINUS

LACERTA

EQUULEUS

PEG

ASUS

PIS

CES

VULPECULA

HERCULES

DRACO

CORONA

BOREALIS

SERPENS

CAPUT

SERPENSCAUDA

SCUTUM

AQUILA

SCORPIU

S

SAGITTARIUS

CA

PRIC

OR

NU

S

AQ

UA

RIU

S

NORMA

ARA

TELESCOPIUM

MIC

RO

SC

OPI

UM PI

SCIS

AU

STRI

NU

S

CO

RO

NA

AU

ST

RA

LIS

APUS

OCTANS

ERIDANUS

PAVO

INDUS

AcruxMimosa Rigel Kent

An

tares

Altair

Vega

Deneb

Hadar

Spica

Arcturus

Achernar

Fom

alh

aut

S_Sky_Guide_TEXT_3ed_02.indd 41 7/5/08 11:31:59 AM

42

Skyview 209 pm, September: weeks one and two

Sidereal time 2000

The south ern sky has its duller spring­time look. The bright stars of the Cross and Pointers are sinking in the south­west, Canopus in Carina is against the south ern horizon, and Achernar in Eridanus is still coming up in the south­east. Of the brighter stars only Fomalhaut in the Southern Fish is high, lying in the south­east and forming a dis tinc tive pattern with some stars of nearby Grus the Crane.

Scorpius is plung ing head­first into the west, with Libra the Scales leading it down and Sagittarius the Archer close behind. Further east are other fainter zodiac signs Capricornus and Aquarius.

Due north glitter the stars of the Winter Triangle: Altair in Aquila the Eagle, Vega in Lyra the Harp and Deneb in Cygnus the Swan. No other bright stars are in sight, but the Great Square of Pegasus, only bright ish but dis tinc tive, has risen above the north­east horizon, with the early stars of Pisces the Fish following it up the sky.

13

5

20

12

19

11

18

10

9

1

2

3

4

0h

12h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

MUSCACRUX

CENTAURUS

VELA

VIR

GO

CARINA

VOLANS

PICTOR

MENSA

DORADO

RETICULUM

HYDRUS

HOROLOGIUM

TUCANA

GRUS

SC

ULP

TOR

CE

TU

S

PHO

ENIX

FORN

AX

HYDRA

TRIANGULUM

AUSTRALECIRCINUS

LUPU

S

LIBR

A

OPHIU

CHUS

LYRA

CYGNUS

SAGITTA DELPHINUS

LACERTA

EQUULEUS

PEGASUS

ANDR

OM

EDA

PIS

CES

VULPECULA

HERCULES

CORO

NA

BOREA

LIS

SERPENS

CAPU

T

SERPENSCAUDA

SCUTU

M

AQUILA

SC

OR

PIUS

SAGITTARIUS

CAPRICORNUS

AQ

UA

RIU

S

NO

RMA ARA TELESCOPIUM

MIC

RO

SC

OP

IUM PIS

CIS

AU

STR

INU

S

CO

RO

NA

AU

STR

ALIS

APUS

OCTANS ERID

ANUS

ERID

AN

US

PAVO

INDUS

AcruxMimosa

Canopus

Rigel Kent

Antares

Altair

Vega

Deneb

Hadar

Achernar

Fom

alh

aut

S_Sky_Guide_TEXT_3ed_02.indd 42 7/5/08 11:32:00 AM

43

Skyview 219 pm, September: weeks three and four

Sidereal time 2100

In the north­west Ophiuchus and Hercules are setting. The Winter Triangle of Vega, Altair and Deneb dom i nates the north­west, with the fainter Great Square of Pegasus in the north­east. Further east still, all of the faint stars of the zodiac sign Pisces the Fish are now in view. With the sur round ing con stel la tions such as Aquarius and Cetus the Whale (just rising), Pisces makes up the ‘wet corner’ of the sky.

In the south, the Cross is low to the south­west. Achernar, the end of the river Eridanus, is cor re spond ingly high in the south­east. Higher still is Fomalhaut, the mouth of the Southern Fish.

In the west, Libra is close to setting and Scorpius is diving down wards, claws first. The line of the zodiac then runs east wards through Sagittarius, Capricornus and Aquarius to the newly risen Pisces.

6

13

5

20

12

19

11

18

10

9

1

2

3

4

12h

0h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEONMUSCA

CRUX

CENTAURUS

CARINA

VOLANSPICTOR

MENSADORADO

RETICULUM

HYDRUSHOROLOGIU

M CAELUM

TUCANA

GRUS

SC

ULP

TOR

CE

TU

S

PHO

ENIX

FOR

NA

X

HYDRA

TRIANGULUM

AUSTRALE

CIRCINUS

LUPU

S

LIBR

A

OPH

IUC

HU

S

LYRA

CYGNUS

SAGITTADELPHINUS

LACERTA

EQUULEUS

PEGASUS

ANDROMEDA

PISC

ES

AR

IES

VULPECULA

HERCULES

SER

PENS

CA

PUT SERPENS

CAUDA

SC

UTU

M

AQUILA

SC

OR

PIUS

SA

GIT

TAR

IUS

CAPRICORNUS

AQ

UA

RIU

S

NO

RMA ARA TELESCOPIUM

MIC

RO

SC

OP

IUM

PIS

CIS

AU

STR

INU

SCO

RO

NA

AU

STR

ALIS

APUS

OCTANS

ERID

AN

US

ERID

AN

US

PAVO

INDUS

AcruxMimosa

Canopus

Rigel Kent

Antares

Altair

Vega

DenebHadar

Achernar

Fom

alha

ut

Mir

a

S_Sky_Guide_TEXT_3ed_02.indd 43 7/5/08 11:32:02 AM

44

Skyview 229 pm, October: weeks one and two

Sidereal time 2200

On the south­east horizon, Canopus, second bright est star in the sky, is making a return, bal anc ing the sinking of the Cross and the Pointers which are now at four or five o’clock. Higher in the south­east sky, Achernar marks the end of the river Eridanus. Fomalhaut in the Southern Fish nears the top of the sky.

In the north­west, the Winter Triangle of Altair (in Aquilia the Eagle), Vega (in Lyra the Harp) and Deneb (in Cygnus the Swan) remains prom i nent. The north­east sky belongs to the Great Square of Pegasus, rep re sent ing both Pegasus and Andromeda.

Further east, the zodiac sign of Aries the Ram has risen. The faint sign Pisces lies mostly above Pegasus, while further west are Aquarius and Capricornus. Sagittarius and Scorpius con tinue their fall down the western sky.

6

13

5

20

12

19

11

18

10

1

2

3

4

12h

0h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

MUSCA

CRUXCENTAURUS

CARINA

VELA

VOLANS

PICTOR

PUPPIS

COLU

MBAMENSA

DORADO

RETICULUM

HYDRUS

HOROLOGIU

M

CAELUM

TUCANA

GRUS

SC

ULP

TOR

CE

TU

S

TAU

RU

S

PHO

ENIX

FOR

NA

X

TRIANGULUM

AUSTRALE

CIRCINUS

LUPUS

LIBR

A

OP

HIU

CH

US

LYRACYGNUS

SAGITTA

DELPHINUS

LACERTA

EQUULEUS

PEGASUS

ANDROMEDA

PISC

ES

ARI

ES

TRIA

NGULUM

VULPECULA

HERCU

LES

SERPENS

CAU

DA

SC

UTU

MAQUILA

SCORPIU

S

SA

GITTA

RIU

S

CAPRICORNUS

AQUARIUS

NO

RMA

ARA

TELESCOPIUM

MICROSCOPIUM

PIS

CIS

AU

ST

RIN

US

CO

RO

NA

AU

STR

ALIS

APUS

OCTANS

ERID

AN

US

PAVO

INDUS

AcruxMimosa

Canopus

Rigel Kent

Antares

Altair

Vega

Deneb

Hadar

Achernar

Fom

alh

aut

Mir

a

S_Sky_Guide_TEXT_3ed_02.indd 44 7/5/08 11:32:03 AM

45

Skyview 239 pm, October: weeks three and four

Sidereal time 2300

In the north­west, the Winter Triangle has begun to set, with Vega in Lyra the Harp first to go. Deneb in Cygnus the Swan will be next, leaving Altair in Aquila the Eagle higher in the sky. In the north, the Great Square of Pegasus is about to cross the merid ian.

Aries the Ram in the north­east, with a dis tinc tive pair of bright ish stars, is the east ern most of the risen zodiac signs. Further west, and running steeply up the sky, lie Pisces, Aquarius, Capricornus and the ‘tea­pot’ Sagittarius. In the west, Scorpius is setting.

The ‘wet corner’ of the sky is over head, stretch ing both north­east and north­west. Constellations such as the Southern Fish, Aquarius, Capricornus, Cetus, Eridanus and Pisces all have watery con nec tions.

14

6

13

5

20

12

19

11

10

1

2

3

4

12h

12h

NORTH

EA

ST

SOUTH

WE

ST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

MUSCA

CRUX

CENTAURUS

CENTAURUS

CARINA

VELA

VOLANS

PICTOR

PUPPIS

COLU

MBA

MENSA

DORADO

RETICULUMHYDRUS

HOROLOGIU

M

CAEL

UM

TUCANA

GRUS

SC

ULP

TO

R

CET

US

TAU

RUS

PHO

ENIX

FOR

NA

X

ER

IDA

NU

S

TRIANGULUM

AUSTRALECIRCINUS

LUPUS

LIBRA

OP

HIU

CH

US

CYGNUS

LYRA

SAGITTA

DELPHINUS

LACERTA

EQUULEUS

PEGASUS

ANDROMEDA

PISCES

ARIES

TRIANGULUM

VULPECULA

SER

PENS

CA

UD

A

SC

UT

UM

AQ

UILA

SCORPIU

S

SA

GIT

TAR

IUS C

APR

ICO

RN

US

AQUARIUS

NORMA

ARA

TELESCOPIU

M

MIC

RO

SC

OPIU

M

PISCISAUSTRINUS

CO

RO

NA

AU

STR

ALIS

APUS

OCTANS

LEPU

S

PAVO

INDU

S

Acrux

Mimosa

Canopus

Rig

el

Rigel Kent

Antares

Altair

Deneb

Hadar

Achernar

Fomalhaut

Mir

a

S_Sky_Guide_TEXT_3ed_02.indd 45 7/5/08 11:32:04 AM

46

Skyview 249 pm, November: weeks one and two

Sidereal time 2400

In the east, the rising of Rigel signals the return of the bril liant con stel la tion Orion the Hunter, announcing that summer is coming. To the north­east, reddish Aldebaran has joined the Pleiades marking Taurus the Bull. Though fainter, the Great Square of Pegasus is prom i nent, strad dling the merid ian. In the north­west, Cygnus is setting, taking Deneb, and Aquila with its bright star Altair is headed the same way.

In the south­west, Scorpius is setting, and the visible zodiac signs run from Sagittarius in the west, through Capricornus, Aquarius and Pisces, to Aries and Taurus in the north­east. The Cross is upside­down against the south ern horizon, but Canopus in Carina and Achernar in Eridanus (in the south­east) and Fomalhaut in the Southern Fish (over head) are prom i nent. The latter makes a lop­sided cross with stars of Grus the Crane.

10

19

1

23

4

5

6

7

11

12

13

14

20

0h

12h

NORTH

EAST

SOUTH

WEST

ECLIPTIC

EQUATOR

Magnitudes

5 4 3 2 1 0 brighter

SouthPole

CHAMAELEON

Hya

des

Pleia

des

MUSCA

CRUX

CENTAURUS

CENTAURUS

VELA

PUPPIS

CARINA

VOLANS

PICTOR

MENSA

DORADORETICULUMHYDRUS

HORO

LOGIU

M

TUCANA

CAEL

UM

PHO

ENIX

COLU

MBA

CAN

IS

MA

JOR

SERPENS

CA

UD

A

TRIANGULUM

AUSTRALE

CIRCINUS

NORMA

ARA

LUPUS

APUS

OCTANS

PAVO

INDUS

GRUS

PISCIS

AU

STRINU

S

MICRO

SCOPIU

M

TELESCOPIUM

SCORPIUS

SAG

ITTARIU

S

OPH

IUC

HU

S

OPH

IUC

HU

S

SCU

TUM

CA

PRICO

RNU

SCO

RON

AAU

STRALIS

LEPU

S

ORI

ON

TAU

RUS

ERID

AN

US

FORN

AX

SCU

LPTO

R

CETUS

PISCES

ANDROMEDA

PERSEUS

ARIES

TRIANGULUM

AQU

ILA

VULPECU

LA

DELPHINUSSAGITTA

EQUULEUS

LACERTA

PEGASUS

AQUARIUS

CYGNUS

Mimosa

Acrux

Rigel Kent

Hadar

Canopus

Siriu

s

Adha

ra

Achernar

Mira

Algol

Ald

ebar

an

Rig

el

Fomalhaut

Altair

S_Sky_Guide_TEXT_3ed_02.indd 46 7/5/08 11:32:06 AM

Using the Sky Charts

The 20 charts in this section cover the whole night sky visible from around 35 degrees south lat i tude in much greater detail than the Skyviews in the pre vi ous section. Each chart is accom pa nied by infor ma tion about the celes tial objects visible in the par tic u lar region of the night sky and about the stories behind the stars and con stel la tions.

To deter mine which of the Sky Charts to use, refer to the large numbers dis trib uted across the Skyviews. For instance, on the Skyview for 9 pm in early June (No. 14), the region near Leo the Lion (in the north-western sky) bears the number 16, indi cat ing that Sky Chart 16 shows this region in greater detail.

There are three groups of charts in this section.

Charts 1 to 4•   Most of the sky area covered by these charts is always above 

the horizon.• These charts are to be read looking to the south.

Charts 5 to 12• These charts are to be read looking to the north. •   The sky areas covered by these charts are above the horizon 

for about 14 hours at a stretch. •   The stars  shown on  these charts will be  found  in a band 

running from east to west and cross ing the sky high up to the north of the zenith.

Charts 13 to 20• These charts are to be read looking to the north.•   The sky areas covered by these charts are above the horizon 

for around 8 to 10 hours at a stretch.•   The stars  shown on  these charts will be  found  in a band 

running from north-east to north-west and cross ing the lower half of the north ern sky.

47

THE NIGHT SKY IN DETAIL

S_Sky_Guide_TEXT_3ed_03.indd 47 7/5/08 11:32:52 AM

CHArT 10 Hours to 6 Hours rA

90 to 45 degrees Dec

This is a crowded corner of the sky in terms of con stel la tions, though none of the stars is bright other than Achernar. This first mag ni tude star, ninth in order of bright ness among the stars, marks the end of the long winding con stel la tion Eridanus the River. This weaving line of faint ish stars (only Achernar is brighter than mag ni tude 3) is the longest of the con stel la tions, and begins way to the north near Orion. Eridanus is most likely a hea venly rep re sen ta tion of the Nile. It is far enough north to have been seen (and named) from Egypt in ancient times.

Grouped about Eridanus and mostly further south are a host of minor star pic tures named much more recently; a couple of birds (a toucan and a phoenix), a male water serpent (Hydrus), a sword fish (Dorado), the ‘table mountain’ (Mensa) and four very dull ones: Pictor (the painter’s easel), Caelum (the engrav ing tool!), Horologium (the clock) and Reticulum (the reticle, a grid used for making star maps). Of these, the most inter est ing is perhaps Phoenix, with a roughly ‘Australia-shaped’ col lec tion of bright ish to medio cre stars lying clock wise of Eridanus.

Of far greater inter est are the two Clouds of Magellan, named after the great Spanish nav i ga tor but not dis cov ered by him. They were seen by the first Portuguese sailors to round the Cape of Good Hope some decades earlier and were known for a time as the Cape Clouds. These two misty patches of light are visible to the naked eye only in a clear dark sky. Both are com posed, like the Milky Way, of vast numbers of sep ar ate stars, as a look through binoc u lars will reveal, but lie beyond the Milky Way, being the nearest star systems or gal ax ies to our own. In the sky they lie roughly equi­dis tant from each other and from the South (Celestial) Pole.

The Large Magellanic Cloud (LMC) lies mostly in the con stel la tion Dorado, tucked on the clock wise side of the tri an gle of stars that covers most of Hydrus. It is about 10 degrees square, the width of a fist at arm’s length in each direc tion (or 20 times the width of the Full Moon). Binoculars will clarify its shape, and should reveal within the Cloud the spider-like Tarantula Nebula (N2070), also called the Great Looped Nebula, which is about the size of the Full Moon. The nebula sur rounds a star called 30 Doradus. It was near to this nebula that the super nova known as 1987A appeared in February 1987.

The Small Magellanic Cloud (SMC), which lies in Tucana, is only one sixth the appar ent size of its neigh bour, and further away (200,000 light years rather than 160,000), but seems brighter. Two degrees (a thumb’s width) clock wise from  the  SMC  lies  one  of  the  finest  glob u lar  clus ters  in  the  heavens,  bet tered  only  by  Omega Centauri. This is 47 Tucanae (N104), spec tac u lar in binoc u lars or smaller tele scopes and aston ish ing in bigger ones. A smaller glob u lar cluster (N362) abuts the SMC on the side away from the pole.

A double star worth seeking is Herschel 3670 in the con stel la tion Reticulum (near 4 hr 30, 63 deg.). A pair of stars (mag ni tudes 5.9, 8.4) are sep ar ated by a large ish 32 seconds of arc. The colour contrast is strong, com monly seen as yellow and blue. In Pictor lies Dunlop 18 (Iota Pictoris); a pair of yellow stars (mag ni tudes 5.6 and 6.4) sep ar ated by 12 arc seconds (near 4 hr 50, 54 deg.).

Horologium boasts a notable Mira­type var i able. R Hor lies close to the border with Eridanus (near 3 hr, 50 deg.) and varies from mag ni tude 4.3 to 14.3 every 404 days.

48

S_Sky_Guide_TEXT_3ed_03.indd 48 7/5/08 11:32:52 AM

49

SouthCelestialPole

MAGNITUDES DEEPSKY OBJECTS

6 5 4 3 12 0 brighter Double stars Variable stars Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

CHAMAELEON

OCTANS

APUS

MENSA

VOLANS CARINA

PUPPIS

COLUMBA

PICTOR

DORADO

CAELUM

RETICULUM

ERIDANUS

ERIDANUS

FORNAX

SCULPTOR

PHOENIX

TUCANA

HYDRUS

INDUS

GRUS

HOROLOGIUM

2070

47 Tuc (104)362

1313

1672

1566

1808

1851

1433

1291

30055

1316

1365 1399

1360

1097

1232

1398

TarantulaNebula

RS

TZR

R

WZ

R

h3670

ig

f

h

ye

s

Y

SN1987A

G

LMC

SMC

Achernar

Canopus

Ankaa

Acamar

R

p

q1

q2

OA

N

G

41

43

18

6h

5h

4h

–30°

–20°

–80°

–70°

–60°

–50°

–40°

–90°

–70° –60° –50° –40°–80°

0h 1h 2h 3h–30° –20°

64

5

23

S_Sky_Guide_TEXT_3ed_03.indd 49 7/5/08 11:32:54 AM

CHArT 26 Hours to 12 Hours rA

90 to 45 degrees Dec

This part of the sky was once ruled by the mighty con stel la tion Argo Navis, the ship Argo. In the Argo the ancient Greek hero Jason and his band of 50 ‘argonauts’ rowed and sailed west ward into the Black Sea in quest of the magical Golden Fleece in the century before the Trojan War. The ram from which the fleece came is rep re sented else where in the sky by the zodiac sign Aries.

Perhaps because it took up so much of the sky, Argo is broken down into four con stel la tions on modern maps; the roughly rec tan gu lar Carina the Keel, the mis sha pen pen ta gon of Vela the Sail, another rec tan gle of stars marking Puppis the Poop, and Pyxis the Mariner’s Compass, which is hard to find. The stars of Puppis and Pyxis lie further away from the South Pole than the other two con stel la tions, and not all of them are marked on this chart (see Chart 7).

Two stars of Vela and two of Carina are com monly grouped to form the False Cross, larger and fainter than the ‘real’ Southern Cross, which lies 40 degrees anti-clockwise, but oriented sim i larly in the sky.

Canopus, the bright est star in the area and the second bright est in the whole night sky, lies in Carina. Many maps show it as marking nothing more impor tant than the end of one of the oars, though more ancient sources place it on the rudder. One expla na tion of the name is that it is from a famous sea captain at the time of the Trojan War, when he com manded the ship of King Menaleus.

Canopus is a guide to the notable semi-regular var i able star L2 Puppis, which lies 10 degrees anti-clockwise and a similar dis tance further away from the pole. L2 Pup shifts from mag ni tude 2.6 to 6.2 (that is, from visible to invis ible with the naked eye) every 141 days. Two notable Mira­type var i ables inhabit Carina, both found close to the 10 hours RA merid ian. R Carinae (near 9 hr 30, 63 deg.) moves from 3.9 to 10.5 and back every 309 days; S Carinae (near 10 hr 09, 61 deg.) moves between 4.5 and 9.9 every 149 days.

Vela con tains a pair of doubles (four stars alto gether), close enough to be in the same field of view (near 10 hr 45, 49 deg.); Herschel (h) 4330 has a yellow 5.1 mag ni tude primary with a blue 8.6 mag ni tude com pan ion 40 arc seconds distant; Herschel (h) 4332 is blue and white, mag ni tudes 7.2, 9.6, sep ar a tion 28 arc seconds. Also within Vela, and occu py ing the most clock wise posi tion among the bright ish stars in that con stel la tion, Gamma Velorum is a rel-a tively easy double; blue-white stars of mag ni tude 1.8 and 4.3, sep ar ated by 41 seconds of arc.

The Milky Way flows across this region of sky, delin eat ing one of the spiral arms of the galaxy in which we live. Against  the  Milky Way,  binoc u lars  will  reveal  some  of  the  bright  and  dark  intri ca cies  of  the  Eta Carinae Nebula (N3372), clock wise from the Southern Cross about 30 degrees (about one hour on an ordi nary clockface) and there-fore about 101⁄2 hours of RA. At mag ni tude 3 and 2 degrees diam e ter (four times the diam e ter of the Full Moon), the nebula is a naked-eye object on dark nights. Several bright star clus ters sur round it.

The star Eta Carinae lies at the heart of the nebula, and is one of the largest, most lumi nous and most unstable stars known. Now at seventh mag ni tude, it is visible only with optical aid, but last century it out shone all but Sirius. It is often thought the star most likely to form the next super nova visible from Earth. The fading of Eta Carinae has dimmed the out lines of the Keyhole Nebula, as the Eta Carinae Nebula was called by John Herschel.

Five degrees pole wards from Eta Carina is the bright open cluster I2602 (also called Theta Carinae), mag ni tude 2 and nearly a degree across. It con tains about 30 blue-white stars. Only 650 light years away, it is one of the closer clus-ters. Another cluster (N3766, known as the Pearl Cluster) lies 10 degrees clock wise of Alpha Crux (or roughly halfway between Alpha Crux and I2602). It is large (75 minutes by 50 minutes) but faint (mag ni tude 7). You might also chase I2391 (Omicron Velorum, mag ni tude 2.5, diam e ter 50), which lies about 10 degrees pole wards and anti-clockwise of Gamma Velorum.

50

S_Sky_Guide_TEXT_3ed_03.indd 50 7/5/08 11:32:54 AM

51

SouthCelestialPole

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

CENTAURUS

VELA

ANTLIA

PYXIS

HYDRA

CRUX

24392527

2477

2547

3201

3132

2546

2997

I.2395

2451

MYAH

R

L

M

S

p

n

R

k

i

l

m

h

ag

N

q

w

Uu

z

xs r

YJ

RQ

O

I

K

L

T

B

C

c

IK

H

G

E

S

B

U

b

c

ez

f

MZ

r

q

w

H

Q

C

D

A

EF

y

M

B

C

EF

Dc

f

g

G

a

b

n

e

S

dh

w

w

H

G

A

F

n

l

u

DE

e

z

Mm

p

i

q

r

st

y

u

A

V

J

Q

PO

N

aT

I

x

e2

b1,2

e1

d

f

t1 t2

z1 z2

k1

l

k2

h1

h2

d1-3

v1v2

D1

D2

C1C2

C3

L1

L2

MUSCA

Mimosa

Acrux

Miaplacides

Aspidiske

Gacrux

Avior

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

WZ

CHAMAELEON

OCTANS

APUS

MENSA

VOLANS

CARINA

PUPPIS

COLUMBA

PICTOR

DORADO

HYI

2070

I.2448

2808

I.2602

3211

2867

I.2391

3144

3532

3293

I.2581

2516

3195

4833

3372

4609

4755

3918

3766

Eta Carinae Nebula

4372

1851

TarantulaNebula

RS

TZ

R

S

Y

SN1987A

G

LMC

Canopus

O

A

N

G

Naos

12h

11h

10h

–30°

–20°

–80°

–70°

–60°

–50°

–40°

–90°

–70° –60° –50° –40°–80°

6h 7h 8h 9h–30° –20°

81

7

34

S_Sky_Guide_TEXT_3ed_03.indd 51 7/5/08 11:32:57 AM

CHArT 312 Hours to 18 Hours rA 90 to 40 degrees Dec

The stars of Crux Australis, the Southern Cross, are well known from their pres ence on the Australian and New Zealand national flags, though it has been sug gested that the con stel la tion, which is the small est in the sky, resem bles more a badly made kite than a cross! Crux, the small est of the offi cial con stel la tions, was formed out of stars of Centaurus by early nav i ga tors of the South Seas, and was offi cially entered on the charts in the six teenth century.

The five main stars in Crux decrease in bright ness moving clock wise around the con stel la tion, begin ning with Acrux at the bottom. Beta Crucis is often called Mimosa (a name for wattle). Gamma Crucis at the top is dis tinctly reddish, even with the naked eye, being a red giant star. The fifth star, Epsilon Crucis, is on the lower right when the Cross is upright.

Acrux is a multi ple star; the two main com po nents being blue-white, mag ni tudes 1.5 and 5, lying 90 arc seconds apart. The brighter star is itself double, but the com po nents are only 4 arc seconds apart and dif fi cult to sep ar ate in small instru ments. Five degrees anti- clockwise from Gamma Crucis, Mu Crucis is an easy double in binoc u lars: two white stars, 35 arc seconds apart, mag ni tudes 4.3, 5.5.

Trailing the Cross in its journey around the south ern sky, and showing the way to it, are the two Pointers. More for mally, the stars are known as Rigil Kentaurus and Hadar (or Agena), or Alpha and Beta Centauri, being the two bright est stars in the con stel la tion of Centaurus the Centaur which sur rounds the Cross on three sides. Centaurs were myth i cal beasts, half man and half horse and often held to be wise and noble. The con stel la tion may rep re sent the centaur Chiron, under whom the hero Jason was edu cated.

The Pointers look about equally bright but are in reality very dif fer ent, Beta being 100 times further way than Alpha and emit ting 10,000 times more light. Alpha is not only the nearest bright star to our Sun, it is also the most Sun-like of the nearby stars, with a very similar abso lute mag ni tude and surface tem per a ture (though about twice the mass and four times the intrin sic bright ness). Alpha is a multi ple; its bright com po nents are white stars (mag ni tudes 1.0 and 1.4) lying 21 seconds apart. The third star in the system, Proxima Centauri, is a dim red dwarf, hard to find at mag-ni tude 11, and lying 2 degrees away from the primary. It is cur rently the nearest star to the Sun.

On the old star charts, the Centaur stands astride the Cross, facing anti-clockwise. The Pointers mark his forelegs and two stars to the upper right of the Cross (when upright), and one imme di ately clock wise from it, locate his hin dlegs. Stars rep re sent ing his upper body lie further away from the Pole and anti-clockwise. In the Centaur’s hand is a spear with which he is dealing with a wolf (Lupus).

Polewards of the Cross we find the small con stel la tion Musca the Fly, with stars in a rough cross shape around Alpha Muscae. Anti­clockwise of the Cross lies the imag i na tively named Southern Triangle (Triangulum Australe), and Ara the Altar, which abuts the Scorpion. Also in the area (but dim) are Norma the Set Square, Circinus the Compasses and Apus the Bird of Paradise.

The region around the Cross is full of sights for users of binoc u lars or small tele scopes. The Milky Way runs behind the Cross, the Pointers, the Triangle and Ara. A large dark nebula dubbed the Coal Sack, and looking like a hole through the Milky Way, touches the Cross between Alpha and Beta Crucis. It is prom i nent on a dark night. Squeezed between the Coal Sack and Beta Crucis is the Jewel Box (N4755), a multi-coloured open cluster of at least 50 stars grouped around the red giant Kappa Crucis. On the other side of the Cross, a diffuse nebula sur rounds the star Lambda Crucis.

In the upper reaches of the Centaur are two sights worth seeking out. They lie less than 5 degrees apart. One is the giant ellip ti cal galaxy Centaurus A (N5128, mag ni tude 6.9), with two semi cir cu lar seg ments sep ar ated by a dark lane of dust. Though rel a tively faint, it is half the width of the Full Moon and among the bright est and largest of the exter­nal gal ax ies (near 13 hr 25, 43 deg.).

The other, lying 4 degrees closer to the pole, is among the real jewels of the south ern sky. The glob u lar cluster Omega Centauri (N5139) is almost the size of the Full Moon, and an easy naked­eye object at mag ni tude 3.8 (near 13 hr 26, 47.5 deg.). Binoculars will reveal its unstar-like fuz zi ness and may reveal indi vid ual stars in out ly ing regions. It is bright because it is close (16,000 light years) as glob u lar clus ters go. Large tele scopes are needed to resolve the hun-dreds of thou sands of stars that fill it.

52

S_Sky_Guide_TEXT_3ed_03.indd 52 7/5/08 11:32:57 AM

53

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

SouthCelestial

Pole

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

LIBRA

LUPUS

HYDRA

NORMA

CIRCINUS

TRIANGULUMAUSTRALE

PAVO

TELESCOPIUM

ARA

SCORPIUS

CORONAAUSTRALIS

ECLI

PTIC

5189

5315

5281 5316 5617

6362

6397

60256087

6067

6744

5139

4560

5822

5662

5882

6124

6193

6388I.4651

6541

6281

6302

62426231

Tr24

5986

5643

5897

I.4406

4945

Omega Centauri

5128

5102

RS

GG

T

S

J

mR

V

QN

M

K

v

X

N

H

Q

R

f

d

z

a

y

1

2

2

3T

58

c1

c

c2a

b

dg

k

he

b

Atria

Rigel Kent

ProximaCentauri

Hadar

Menkent

Shaula

Lesath

CENTAURUS

VELACRUX

R

Uu

T

I

K

S

B

w

HG

A

F

n

lu

D

E

e

z1

z2

C1C2

C3

MUSCA

Mimosa

Acrux

Gacrux

CHAMAELEON

OCTANS

APUS

MENSA

CARINA

HYI

I.2602

3532

3195

4833

4609

4755

3918

3766

4372

TZ R

S

18h

17h

16h

–30°

–20°

–80°

–70°

–60°

–50°

–40°

–90°

–70° –60° –50° –40°–80°

12h 13h 14h 15h–30° –20°

102

9

41

S_Sky_Guide_TEXT_3ed_03.indd 53 7/5/08 11:32:59 AM

CHArT 418 Hours to 24 Hours rA 90 to 40 degrees Dec

This chart indi cates how unevenly the wonders of the heaven are spread. In com par i son with the glories of the stretch of sky lying clock wise from it, this region is barren, with no bright stars and few con stel la tions of inter est. It is all but bereft of bright nebulae and open clus ters; the Milky Way, along the length of which those sights are con cen trated, just clips one edge.

The con stel la tions here are mostly of modern origin and gen er ally devoid of leg en dary asso ci a tions. A few birds are rep re sented by group ings of faint stars (Pavo the Peacock, Grus the Crane and much of Tucana the Toucan) along with Indus the Indian and a clutch of sci en tific instru ments (Telescopium, Octans and a bit of Microscopium).

Pavo is about the only ast er ism here with a story. Ancient legend says that Argos, builder of the mighty Argo which sails nearby, was changed into a peacock when the ship was taken into the heavens. The brighter stars of Grus form a notable lop sided pattern with Fomalhaut in the Southern Fish further away from the Pole (see Chart 12).

Octans the Octant (an instru ment for meas ur ing angles) is of note as the con stel la tion in which the South Celestial Pole cur rently lies. The fifth mag ni tude star Sigma Octantis is the naked-eye star closest to the Pole, and so is the south-ern equiv a lent of Polaris the North Pole Star (though Polaris is much brighter).

Among the few things worth search ing for with binoc u lars are the largish glob u lar cluster N6752 (mag ni tude 5.4, 20 diam e ter) in Pavo (near 19 hr 10, 60 deg.), and about 5 degrees pole wards, the mag ni tude 8.5 galaxy N6744. Dunlop (delta) 227 in Telescopium (near 19 hr 50, 55 deg.) is worth a look; an attrac tive double, yellow and white, 5.8 and 6.5, sep ar a tion an easy 23 arc seconds.

54

S_Sky_Guide_TEXT_3ed_03.indd 54 7/5/08 11:32:59 AM

55

SouthCelestial

Pole

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

M55

6752

I.1459

Y

T

SX

RR

24

SCL

PISCISAUSTRINUS

MICROSCOPIUM

SAGITTARIUS

CAPRICORNUS

Peacock

Alnair

Arkab

Rukbat

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

TRA PAVO

TELESCOPIUM

ARA

SCORPIUS CORONAAUSTRALIS

6362

6397

6744

6723

6388

I.4651

6541

Q

Atria

CHA

OCTANS

APUS

MENSA

TUCANA

INDUS

GRUS

47 Tuc (104)

362

55

TZ

R SMC

AnkaaPHOENIX

HYDRUS

ECLIPTIC

227

0h

23h

22h

–30°

–20°

–80°

–70°

–60°

–50°

–40°

–90°

–70° –60° –50° –40°–80°

18h 19h 20h 21h–30° –20°

123

11

12

S_Sky_Guide_TEXT_3ed_03.indd 55 7/5/08 11:33:01 AM

CHArT 50 Hours to 3 Hours rA

40 to 10 degrees Dec

When we survey this stretch of night sky, we are looking at right angles to the plane of the galaxy. The South Galactic Pole (SGP) lies here (in Sculptor near 0 hr 50, 27 deg.). So we are well away from the riches of the Milky Way. Bright stars, clus ters and nebulae are rare.

On the other hand, we are able to look almost unim peded into inter ga lac tic space, and so glimpse some of the nearer exter nal gal ax ies (extra ga lac tic nebulae) hidden from us in other parts of the sky by the rich ness of our own star system. These lie mostly in Sculptor and Fornax. The same is true around the North Galactic Pole, which lies in Coma Berenices (see Chart 17).

The largest and bright est con stel la tion here, cov er ing most of the region, is Cetus the Sea Monster (or Whale), fourth largest of all the con stel la tions (after Hydra, Virgo and Ursa Major). Cetus was com monly shown in old star pic tures as swim ming in the nearby river Eridanus or resting on its bank. According to ancient legend, Cetus was the beast sent to devour the maiden Andromeda, so it is linked to con stel la tions which lie further north in the sky (see Chart 13).

The stars of Cetus form two rough poly gons. The larger to the south-west makes up the body of the beast, the smaller to the north-east (where it abuts Aries and Pisces) forms the head. Beta Ceti at mag ni tude 2.4 is usually the bright est star in the con stel la tion (Alpha Ceti bears the name Menkar, meaning ‘nose’).

Of far more inter est is Omicron Ceti, lying about 30 degrees north-east of Beta, halfway along the creature’s neck. Otherwise known as Mira (the Wonderful Star), this was the first star observed to change its bright ness over time. Its status as a ‘var i able star’ was estab lished in the mid-seven teenth century. Over a period of 11 months it moves from mag ni tude 2 to mag ni tude 10 and back again. At its bright est it out shines Beta; at its faint est it becomes invis ible in binoc u lars. Many ‘Mira variables’ are found in other parts of the sky. 

South of Cetus lie more modern con stel la tions; Fornax the Furnace and Sculptor the Sculptor’s Chisel. These are faint but contain numbers of gal ax ies, some of which can be seen in binoc u lars. Two such lie in Sculptor; N55 (mag-ni tude 7.4, near 0 hr 15, 39 deg.) and N253 (mag ni tude 7.2, near 0 hr 50, 25 deg.). None of the numer ous gal-ax ies in Fornax are brighter than mag ni tude 8.9.

Close to the eastern edge of Fornax lies the rel a tively large (one third diam e ter of the Moon) plan e tary nebula N1360 (mag ni tude 9.4) with a bright central star (near 3 hr 30, 26 deg.). Polewards of Fornax lies the double star Theta Eridani (near 3 hr, 40 deg.), with a pair of white or yellow stars (mag ni tudes 3.4, 4.4) sep ar ated by 8.5 arc seconds.

56

S_Sky_Guide_TEXT_3ed_03.indd 56 7/5/08 11:33:01 AM

57

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

AQUARIUS

CETUS

PISCES

PEGASUS ARIES

PSA

HOROLOGIUM

TAUECLIPTIC

613

288SGP

253

247

RS

T

R

99

7

2

98

AlreschaMenkar

Mira

Baten Kaitos

Deneb Kaitos

TX

XZ

30

AR

Z

M77

ERIDANUS

ERIDANUS

FORNAX

SCULPTOR

PHOENIX

1316 1365

1399

1097

1232

i

g

fh

1291

y

e

Acamar

s

55

Ankaa

300

13601398

GRUS

7793

–40°

–30°

–20°

–10°

0°

+10°

–40°

–30°

–20°

–10°

0°

+10°

23h 0h 1h 2h 3h 4h

0h 1h 2h 3h

612

13

1

S_Sky_Guide_TEXT_3ed_03.indd 57 7/5/08 11:33:03 AM

CHArT 63 Hours to 6 Hours rA

40 to 10 degrees Dec

Orion the Hunter, one of the glories of the heavens and perhaps the best known of all con stel la tions, lies at the north-ern end of this stretch of night sky, just west of the Milky Way. Its stars strad dle the celes tial equator, always rising and setting due east and west. The sight of this majes tic con stel la tion rising late in the evening is a sign that the Southern Hemisphere summer is at hand.

In the centre of the group is the well-known ‘saucepan’, though the three bright ish stars marking the base of the pan actu ally rep re sent Orion’s belt and the handle is his sword. The jewel in the sword is the pale green glow of the Orion Nebula (M42/N1976). This shows up pink or red in most photo graphs due to the dif fer ent colour sen si tiv ities of the human eye and photo graphic film. Film picks up the red glow from hydro gen, while the eye is more sen si tive to the green colour of glowing oxygen. But it is a stun ning sight, what ever you use to view it. Strangely, Galileo did not mention it when first viewing the night sky with his tele scope in 1609.

M42 (and nearby M43/N1982 which is part of the same nebula) lies about 1300 light years away. It is a ‘stellar nursery’ like many such nebulae. Imbedded in the 20-light-year-wide cloud of gas and dust is a cluster of (at least) four newly hatched blue stars (‘the Trapezium’), which appear as one to the naked eye (Theta Orionis). Other bright-ish stars and star clus ters are grouped around, making the area a great sight in binoc u lars. For example, the cluster N1980 (mag ni tude 2.5, diam e ter 20) marks the end of the sword.

N1980 con tains a couple of multi ple stars, includ ing the double Iota Orionis, with stars of mag ni tude 3 and 7 sep ar ated by 12 arc seconds. N1981 is an open cluster to the north (nearer the belt)

Surrounding the ‘saucepan’ are bright stars rep re sent ing Orion’s body. When Orion is highest in the sky, early on summer even ings, we in the Southern Hemisphere see him stand ing on his head. To the north the red giant Betelgeuse (cur rently tenth bright est among the stars) and the fainter Bellatrix (the Female Warrior) mark the arms and shoul­ders; to the south the bril liant blue-white Rigel (seventh bright est) locates one of his feet. Betelgeuse means ‘arm’ or ‘shoulder’, Rigel means ‘foot’.

When Orion is rising, Rigel is always the first bright star of the con stel la tion to be seen from south ern lat i tudes. Betelgeuse is a var i able star like many red giants, and is often fainter than Rigel, even though it, not Rigel, is listed as Alpha Orionis. Betelgeuse shifts between mag ni tudes 0.4 and 1.3 over a period of around seven years.

Orion is a hunter, warrior or giant in the star stories of many cul tures. Traditional pic tures in our culture have him armed with a club and net, accom pa nied by two dogs (Canis Major and Canis Minor) and fight ing with a bull (Taurus). Those animals are on adjoin ing pieces of sky.

The rest of the region is dull in com par i son. Lepus the Hare, with a quad ri lat eral of bright ish stars, is beneath the Hunter’s feet, with Columba the Dove further south again. East of Orion are the head wa ters of Eridanus. Much of this stretch of sky is taken up with the mean der ings of the hea venly river. It takes a sharp turn around Fornax which intrudes from the west. Stars of Canis Major and Monoceros the Unicorn border this stretch of sky to the east, with Taurus and the head of Cetus the Sea Monster to the north and west.

Delta Orionis (the most west erly of the stars in the Belt) is a wide double (2.2. and 6.8, white and violet, 53 seconds of arc). The region has a couple of Mira­type var i ables, R Lep (from 5.5 to 11.7 in 432 days, near 5 hr, 15 deg.) and U Ori (4.8 to 12.6 every 372 days, near 5 hr 55, 20 deg.). The Orionids meteor shower, asso ciated with Comet Halley, emerges from the north-eastern part of Orion (close to its border with Gemini) around 16 to 27 October, peaking on 22 October.

58

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59

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

1535

Phact

Wazn

Zaurak

Beid

Keid

Cursa

Arneb

Nihal Mirzam

Furud

Rigel

Betelgeuse

Bellatrix

Saiph

Meissa

Alnilam

Alnitak

Mintaka10

32

SX

M79

I.418

S

RX

54

53

M42 / M43Orion Nebula

1981

1980

1973/75/77

2232

I.2165

V

T

29

8

1662

M78

2024

I.434Horsehead Nebula

W

32

88

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

PUPPIS

COLUMBA

PICTOR

CAELUM

ERIDANUS

CANIS MAJOR

LEPUS

MONOCEROS

ORION

CETUS

ARIES

TAURUS

FORNAX

PHOENIX HOROLOGIUM

1808

1851

13161365

1399i

g

fh

1433

1291y

e

C

1232

s

Acamar

13601398

109741

43

Menkar

Z

M77

–40°

–30°

–20°

–10°

0°

+10°

–40°

–30°

–20°

–10°

0°

+10°

2h 3h 4h 5h 6h 7h

3h 4h 5h 6h

75

14

1

S_Sky_Guide_TEXT_3ed_03.indd 59 7/5/08 11:33:05 AM

CHArT 76 Hours to 9 Hours rA

40 to 10 degrees Dec

This region of sky is dom i nated by the pres ence of stars rep re sent ing two dogs. They could rep re sent many dif fer ent dogs, such as Cerebus the three-headed dog that guarded the way to Hell, but they are usually thought of as the com-pan ions of Orion the Hunter to the west.

Between Canis Major (the Big Dog) and Canis Minor (the Little Dog) runs the Milky Way, while between the Little Dog and his master are incon spic u ous stars belong ing to Monoceros the Unicorn. The open cluster N2244, close to Eta in Monoceros (near 6 hr 30, 15 deg.), is a naked-eye object, at 4.8 mag ni tude, with 16 stars in a huddle visible with optical aid. Powerful tele scopes reveal the sur round ing Rosette Nebula (N2237), the faintly glowing cloud of gas from which the stars formed.

Both the Dogs are worth watch ing. Alpha Canis Majoris is Sirius, the bright est star in the sky other than the Sun. Its name means the ‘shining one’ or ‘scorch ing one’. Old pic tures have it marking the eye or heart of the Dog. Beta Canis Majoris or Mirzam nearby is a front leg and a tri an gle of bright ish stars to the south show the hind quar ters. The bright est of these, Adhara, is the second bright est star in the con stel la tion, even though it is listed only as Epsilon.

Sirius is one of the nearest stars, lying less than nine light years from the Sun. It was an impor tant element in the cal en dars of ancient peoples. The first appear ance of Sirius (or Soothis) in the rays of the rising Sun (the helical rising) was taken by the Egyptians of 2000 BC as a sign that the Nile was about to flood.

The less spec tac u lar Little Dog has Procyon, eighth on the list of bright est stars. Beta Canis Minoris, a few degrees away, makes a dis tinc tive pairing. Both Sirius and Procyon have faint white dwarf com pan ions and are among the 20 stars lying within 12 light years of the Sun

Two of the four con stel la tions that for merly made up Argo Navis (the Ship Argo) are in this part of the sky; namely, the roughly rec tan gu lar Puppis the Poop, which lies south­east of Canis Major and, to the east of Puppis, the incon­se quen tial  Pyxis the Compass. The other two star groups (Vela the Sail and Carina the Keel) are further south. Intruding into the region from the east is the head of Hydra the Water Snake, lying east of Canis Minor.

The pres ence of the Milky Way ensures the avail abil ity of sky sights worth inves ti gat ing with the help of binoc u lars. These include the fol low ing open clus ters:

•   N2451 (mag ni tude 2.8, diam e ter 50 seconds of arc), just west of the Milky Way in the midst of Puppis.

•   N2354 and N2362,  two clus ters  among  the  rump stars of Canis Major, with N2354 both fainter and larger (mag ni tude 6.5, diam e ter 20) than its very near neigh bour (mag ni tude 4.1, diam e ter 8).

•   N2287 (M41) (mag ni tude 4.1, diam e ter 38) about 4 degrees south of Sirius.•   N2423 (M47) on the Milky Way at the north ern end of Puppis (mag ni tude 4.4, diam e ter 25).

N2437 (M46) is nearby (magnitude 6.1, diam e ter 20).•   N2548 (M48) (mag ni tude 5.8, diam e ter 54) east of the Milky Way on the Hydra/Monoceros 

border.Two double stars are asso ciated with M47; Struve (sigma) 1121 has com po nents both mag ni tude 8 lying 8 seconds of arc apart; in Struve (sigma) 1120, stars of mag ni tude 5.6 and 9.5 are sep ar ated by 20 arc seconds.

If you are looking for other double stars, k Puppis, at the north ern end of Puppis (5 degrees east of Delta Canis Majoris), boasts a pair of matched fifth mag ni tude yellow stars lying about 10 arc seconds apart. Nearby Adhara (Epsilon CMa) is also double but a much tougher call, with mag ni tude 1.5 and 7.4 stars sep ar ated by 7.5 seconds of arc. 

60

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61

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

PICTORCAE

LEPUS CANIS MAJOR

CANIS MINOR

ORIONMONOCEROS

LEO

CANCER

2354

M41

2362

23532343

M50

2301

2244

2237Rosette Nebula

2264

R

U

Wazn

Phact

Nihal

Arnab

Alphard

Naos

Procyon

Gomeisa

Acubens

Mirzam

Sirius

FurudAdhara Aludra

Wezen

Saiph

Betelgeuse

AlnilamMintaka

Meissa S

10

1097

11201121

M93

M46

M472423

2440

2438

2539

n

m

k

p3

12

16

11

M67

M48

BC

C

14

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

VELA

ANTLIA

PYXIS

HYDRA

2527

2467

2546

r

q

w

G

S

w

x

k1lk2

2997

AH

ga

b

n

e d

h

h1

h2

C

D

A

E

M

JQ

P O

N

aT

I

L1

L2

z

y

PUPPIS

COLUMBA

1851

2439

24772451

bc

ez

f

MZ

F yd1-3

v1v2

2232

Alnitak

SX

M79

S

M42 / M43Orion Nebula

1981

1980

1973/75/77

I.2165

V

T

8

10

13

M78

2024

I.434 HorseheadNebula

1808

–40°

–30°

–20°

–10°

0°

+10°

–40°

–30°

–20°

–10°

0°

+10°

5h 6h 7h 8h 9h 10h

6h 7h 8h 9h

86

15

2

S_Sky_Guide_TEXT_3ed_03.indd 61 7/5/08 11:33:07 AM

CHArT 89 Hours to 12 Hours rA

40 to 10 degrees Dec

There is not a lot to note in this part of the sky, lying as it does well east of the Milky Way and south of the eclip tic. A little of the Zodiac sign Virgo the Young Maiden lies to the north-east, hosting (at the present epoch) the north ern autumn equinox. This lies where the eclip tic, pushing south­east, cuts the celes tial equator at the merid ian making 12 hours of RA.

Much of it is taken up with the long line of stars marking Hydra the Female Water Snake, one of the leg en dary foes of the hero Hercules. Orange-coloured Alpha Hydrae, at mag ni tude 2, stands out due to the lack of other bright stars near it. Its name Alphard means (appro pri ately) ‘the sol i tary one’. Some 15 degrees north-west near Cancer the Crab, a small col lec tion of faint ish stars indi cates the beast’s head. The tail of the water snake con tin ues to the east, winding past Corvus the Crow and almost to Libra.

Though  faint, Hydra  can boast of being  the  largest  of  the  rec og nised 88  con stel la tions. Covering 1300  square degrees, it sur passes Virgo, Ursa Major, Cetus and Hercules, the biggest of the rest. Hydra stretches a quarter of the way around the sky, from east of Canis Major to just north of Centaurus.

The rest of the region is taken up with faint and gen er ally unmem or able con stel la tions; Sextans the Sextant and Antlia the Air Pump (all sorts of sci en tific instru ments find a place among the south ern stars!), and Crater the Cup. Crater does have a story linking it to Hydra and also to Corvus to the east. The Crow was sent by his master Apollo to fetch a drink. He dallied by a fig tree, waiting for the fruit to ripen. Being late back, he blamed the snake for delay ing him.

Worth search ing for with binoc u lars or a small tele scope is the plan e tary nebula N3242, located some 12 degrees south-east of Alphard (that is, near 11 hr 30, 18 deg.). At mag ni tude 7.8, it is among the three bright est such objects in the sky. From its appear ance, it is some times dubbed ‘the ghost of Jupiter’ (and may help to explain the mis lead ing term ‘plan e tary nebula’!). Twenty degrees almost due south, on the Antilla/Vela border, lies N3132, another plan e tary nebula rated at magnitude 9 but with a bright central star.

62

S_Sky_Guide_TEXT_3ed_03.indd 62 7/5/08 11:33:08 AM

63

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

PYXIS

CRATER

CORVUS

VIRGO

LEO

SEXTANS

CANCER

ECLIPTIC

Naos

Alphard

Regulus

Alkes

Zaniah

Zavijava

Algorab

Gienah

Alchiba

CENTAURUSVELA

HYDRA

HYDRA

B

r

q

G

S

I

n

l

u

D

i

3132

U

qr

3201

p

s

t

N

k1l

k2

C1

C2

h1

h2

w

cfg

a

ed

hw

ANTLIA

2997

z

m

y

u

PUPPIS

b1

b2

b3

3242

U

3115

3521

VY

31

p1

X1

X2 p

M68

3585

3621

R

M61

4365

4371

12

M67 Acubens

–40°

–30°

–20°

–10°

0°

+10°

–40°

–30°

–20°

–10°

0°

+10°

8h 9h 10h 11h 12h 13h

9h 10h 11h 12h

97

16

2

S_Sky_Guide_TEXT_3ed_03.indd 63 7/5/08 11:33:09 AM

CHArT 912 Hours to 15 Hours rA 40 to 10 degrees Dec

With the eclip tic passing though this zone of sky, we have on display one of the more dis tin guished of the signs of the Zodiac, Virgo the Young Maiden. Rated as the second largest of the con stel la tions, Virgo meas ures more than 30 degrees (three fist widths) in both direc tions. The Sun in its yearly journey through the zodiac reaches the western parts of Virgo around 21 September, which is the spring equinox for the Southern Hemisphere (the autum nal equinox for north ern lat i tudes).

The stars of Virgo are not out stand ingly bright, other than the blue-white Spica, which is almost on the eclip tic. In dif fer ent cul tures, Virgo could stand for any number of young and inno cent maidens. In the best-known rep re sen-ta tion, Virgo is a goddess of spring or of the harvest, perhaps Persephone, the daugh ter of Ceres. Spica rep re sents an ear of wheat in her hand. In other pic tures, Virgo is the blind folded Justina or Astraea, the goddess of justice, weigh ing truth and inno cence on the scales that form the zodiac sign Libra, which lies to the east.

The north-western sector of Virgo, together with parts of con stel la tions further north, is notable for the pres ence of a major col lec tion of exter nal gal ax ies, known as the Virgo Cluster and con tain ing many hun dreds of ‘island universes’ at dis tances esti mated at 40 or 50 million light years. Some of these are visible as faint smudges in small tele scopes or even binoc u lars. The bright est is N4472 (M49) in Virgo, at mag ni tude 8.4 (near 12 hr 30, 8 deg.). Some 20 gal ax ies at mag ni tude 10 or brighter can be found in the 10 degree square patch of sky north of M49, with the largest in actual size being the giant ellip ti cal galaxy M87 (N4486).

As for other con stel la tions in the area: the dis tinc tive rhom boid of second and third mag ni tude stars rep re sent ing Corvus the Crow  lies  south­west  of  Virgo. On  the Virgo/Corvus  border  (near  12 hr 40, 12 deg.) lies N4594 (M104), the famous ‘Sombrero Hat’ galaxy (mag ni tude 8.3, diam e ter 9).

South of Corvus sprawls the tail of Hydra, the female water snake, the rest of which lies to the west. The story linking Hydra, Corvus and Crater is told in the text for Chart 8. One inter est ing scale fallen from the tail is N5236 (M83), one of the bright est exter nal gal ax ies at mag ni tude 7.5 (diameter 11). It lies face on to the viewer (near 13 hr 37, 30 deg.).

64

S_Sky_Guide_TEXT_3ed_03.indd 64 7/5/08 11:33:09 AM

65

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

CRATER

CORVUS

VIRGO

LEO BOOTES

SERPENSCAPUT

VELA

ANT

Porrima

Vindemiatrix

Spica

Zubeneschamali

Zubenelgenubi

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

LIBRA

LUPUS

HYDRA

5882

5128

5102 zy

1

2

3T

58

2

d

d g

e

5986

GG

kh

5643I.4406

a

5897

c1c2

a

b

Menkent

5139 OmegaCentauri

CENTAURUS

Bi

n

lu

D

Zaniah

Zavijava

Algorab

Gienah

Alchiba

M5

S

109 110

16

M83

5068

R

r

M104

Sombrero Galaxy

4699

4697

4753

M49

4636

5248

M60M59

45264535

X1

X2

p

M68

3621

R

R

M61

4365

4371

–40°

–30°

–20°

–10°

0°

+10°

–40°

–30°

–20°

–10°

0°

+10°

11h 12h 13h 14h 15h 16h

12h 13h 14h 15h

108

17

3

S_Sky_Guide_TEXT_3ed_03.indd 65 7/5/08 11:33:11 AM

CHArT 1015 to 18 Hours rA

40 to 10 degrees Dec

In one of the most spec tac u lar regions of the night sky, we here reach the Milky Way at its widest and densest, and dis cover the stun ning con stel la tion Scorpius the Scorpion. For once little imag i na tion is needed to see the crea ture among the stars. The hook of stars that rep re sents the Scorpion’s tail cer tainly invites that inter pre ta tion, but other images are pos sible. The New Zealand Maoris saw in it the fish hook which one of their leg en dary heroes baited with his own blood and then dragged up the South Island from beneath the sea.

In legend, the Scorpion and Orion the Hunter were deadly enemies, with the beast sting ing Orion to death. So one is always rising as the other sets. The heart of the Scorpion is marked by the red giant star Antares (Alpha Scorpii), so named from its sim i lar ity in colour to the planet Ares (Mars). A close approach of Mars and Antares (which happens every few years since Antares lies very close to the eclip tic) will soon confirm the com par i son.

A degree or so west of Antares lies the glob u lar cluster N6121 (M4), one of the larger and brighter exam ples at mag ni tude 5.8 and diam e ter 26. A line of three bright stars west of Antares marks the creature’s claws. The tail, com-plete with a close pair of stars to indi cate the sting, coils towards the south­east, lying across the Milky Way. The brighter of the ‘sting stars’ is Shaula (Gamma Scorpii), second bright est in the con stel la tion.

This stretch of sky has many good targets for binoc u lars. North-east of the sting are a pair of notice able open clus-ters: N6405 (M6, the Butterfly Cluster, mag ni tude 4.2, diam e ter 33), and a few degrees away, the larger and brighter N6475 (M7, mag ni tude 3.3, diam e ter 80). Brighter but smaller than either of these is N6231 (mag ni tude 2.6, diam-e ter 26), which lies on the curve of the Scorpion’s tail. Very close and just to the north is the open cluster Trumpler 24 (mag ni tude about 5, diam e ter 60).

Among the double stars visible in binoc u lars is Beta Scorpii, marking the left claw (mag ni tudes 2.6 and 4.9, sep-ar a tion 13 seconds of arc). Antares is itself double, but with the primary much brighter than the sec on dary and only 3 seconds away, it is a chal lenge even in a 80 mm tele scope.

North-west along the eclip tic, between Scorpius and Virgo the Young Maiden (see Chart 9), two bright ish stars almost a fist width apart, together with a few fainter ones further east, make up the zodiac sign Libra the Scales, almost cer tainly those of Justice. In some ancient maps, the stars of Libra are blended with those of Scorpius to produce greatly enlarged claws. In fact, the usual names for these two stars mean ‘the north ern claw’ and ‘the south ern claw’. Alpha Librae is a very wide double, with the com po nents 3.9 apart, but the mag ni tudes (2.8 and 5.2) mean most people will need binoc u lars.

Scorpius played a key role in the devel op ment of astron omy. Here in 134 BC the Greek astron o mer Hipparchos saw a ‘new star’ (a nova), the first on record. This led him to compile a detailed star map (so he could detect any other ‘new stars’). Comparing his charts with those from Babylon 2000 years before led to dis cov er ies like the pre ces sion of the equinoxes.

Although Scorpius is a zodiac sign, most of it lies way off the eclip tic to the south. The Sun, Moon and planets, when in this region, are likely to be located not in Scorpius but in the south ern parts of the con stel la tion of Ophiuchus the Serpent-Holder, which lies imme di ately to the north. A long polygon of stars marks where a man is appar ently wres-tling with a serpent, while the beast itself rates sep ar ate star group ings to indi cate its head (Serpens Caput to the west) and its tail (Serpens Cauda to the east.) The bright est star in the con stel la tion (Rasalhague or ‘the head of the serpent charmer’) can be found where Ophiuchus con tin ues to the north on Chart 18.

Ophiuchus, like many star signs, has more than one inter pre ta tion. One is that it rep re sents Aesculapius, the ship’s doctor on the Argo and the founder of modern med i cine. This was the man who tried to revive Orion after he was killed by the sting of the Scorpion. The serpent is another symbol of medical wisdom.

Binocular sights in Ophiuchus include the open cluster I4665 (mag ni tude 4.2, diam e ter 70), which lies just north of the second bright est star in the con stel la tion (that is, near 17 hr 50, 8 degrees).

66

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67

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

TEL

SAGITTARIUS

OPHIUCHUS

SERPENS CAUDASCT

SERPENS CAPUT

HERCULES

VIRGO

BOOTES

Alnasl

Kaus Media

Kaus Australis

Kaus Borealis

Graffias

Antares

Rasalhague

Cebalrai

Sabik

Yed Prior

Unukalhai

Yed Posterior

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

LUPUS

HYDRA

NORMA

SCORPIUS

CORONAAUSTRALIS

ECLIPTIC

63886541

6281

6302

6242

6231

Tr24

5897

2

58

c1 c2 Shaula

Lesath

NH

6124

RS

5986h

GG

k

5643I.4406

LIBRA

a

b

5882

dg

e

Menkent

CENTAURUS

Zubeneschamali

Zubenelgenubi

M4

M80

M107

M10

M12

M14

U

48

M22M28

M69

M25

M18

M17

M16

M24Star Cloud

OmegaNebula

Eagle Nebula

M70

I.4776

M62

M19

M9M23

M6

6383

M7

M8

M20M21

6530

LagoonNebula

TrifidNebula

BM

UY

Y

RS

X

W

G

Q

RR

45

36

44

6572

I.46656633

U68

59

72

7067

M5

109110

16

–40°

–30°

–20°

–10°

0°

+10°

–40°

–30°

–20°

–10°

0°

+10°

14h 15h 16h 17h 18h 19h

15h 16h 17h 18h

119

18

3

S_Sky_Guide_TEXT_3ed_03.indd 67 7/5/08 11:33:13 AM

CHArT 1118 Hours to 21 Hours rA 40 to 10 degrees Dec

Between Scorpius and the next zodiac sign, Sagittarius the Archer, at a point on the merid ian marking 18 hours of right ascen sion, the eclip tic reaches its maximum dis tance (23.5 degrees) south of the celes tial equator. The Sun, arriv­ing at this point around 21 December, then stands at the summer sol stice for the south ern hemi sphere, marking the longest day of the year. It follows that these same stars will be passing over head at mid night six months earlier, around the end of June.

Interestingly, at this same point the eclip tic crosses the galac tic equator, a line running down the centre of the Milky Way. Galactic lon gi tude here is less than 10 degrees, indi cat ing that the core of our wheel­shaped galac tic system lies behind the stars in this region of the sky. A visual clue is the appear ance of the Milky Way itself. Between Scorpius and Sagittarius it is wider and denser than at any other point along its length.

Sagittarius the Archer stands in front of the Milky Way. A number of not very bright stars form a shape more sug­ges tive of a teapot than a Centaur firing an arrow at the heart of the Scorpion, as the old star pic tures show. Still, the shape is quite strik ing. The bright est star is Epsilon Sagittarii, which is called Kaus Australis or the ‘south ern bow’. Gamma Sagittarii has the name Alnasl, which means ‘the head of the arrow’, though the pedan tic might say that the arrow looks like it will miss.

From Sagittarius, the line of the Milky Way takes us north­east, through Serpens Cauda (the Tail of the Serpent) to Aquila the Eagle. Its first mag ni tude star Altair is flanked by a fainter star. For more on Aquila see Chart 19.

South of Aquila lies the tiny con stel la tion of Scutum the Shield, notable mostly from the open cluster N6705 (M11, ‘the Wild Duck nebula’, mag ni tude 6, diam e ter 10 minutes of arc). Binoculars show a misty patch, tele scopes a glit-ter ing spray of more than 100 stars, fanned out like a flight of wild birds.

For much of its length in this region of the sky the Milky Way appears split by a great cleft. This reveals the pres ence of vast clouds of dust hanging in space in front of the Milky Way, cutting off the light from the stars behind. Binoculars will reveal some thing more; many bright nebulae and star clus ters seen against the light and dark of the Milky Way. These objects, like stars in general, are con cen trated into the plane of the galaxy. Even with binoc u lars these can be a fine sight. The view through a small tele scope is even better.

This stretch of sky has an extraor di nary con cen tra tion of Messier objects (see page 19), though indi vid u ally brighter objects are found else where. In a mere 10 degrees of arc along the galac tic equator, begin ning at the south­east corner of Serpens Cauda and moving south-west, we find:

•   M16, the open cluster N6611, mag ni tude 6.0, diam e ter 21.•   M17, the ‘Swan Nebula’ N6618, mag ni tude 6.0, diam e ter 25.•   M18, the open cluster N6613, mag ni tude 6.9, diam e ter 8.•   M24, a ‘star cloud’, mag ni tude about 2 and 2 degrees by 1 degree in size.•   M21, the open cluster N6531, mag ni tude 5.9, diam e ter 15.•   M20, the ‘Trifid Nebula’ N6514, mag ni tude 6.3, diam e ter 30.•   M8, the ‘Lagoon Nebula’ N6523/30, mag ni tude 4.6, diam e ter 90.

Both the Lagoon and Trifid Nebulae have small clus ters of bright, young, blue stars within them. It is the ultra vi o let light pouring from these stars that makes the nebulae glow.

Nor is that all the region offers. To name just a few others: 5 or 6 degrees east of M21 is the glob u lar cluster M22 (N6656, mag ni tude 5.1, diam e ter 24). M22 is com monly ranked third in impres sive ness among glob u lar clus ters, behind Omega Centauri (see Chart 3) and 47 Tucanae (see Chart 1). A couple of degrees east of M24 is M25 (the open cluster I4725, mag ni tude 4.6, diam e ter 30). And 10 degrees south­west of M8 (close to the sting of the Scorpion) are the open clus ters M7 and M6.

68

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69

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

ARA

OPHIUCHUS

OPHIUCHUS

SCUTUM

AQUILA

DELPHINUS

AQUARIUS

EQUULEUS

Nunki

Altair

Alya

Alshain

Tarazed

Kitalpha

Dabih

Algedi

Ascella

PISCISAUSTRINUS

MICROSCOPIUM

CAPRICORNUS

Arkab

Rukbat

24

TELESCOPIUM

SCORPIUS

M55

M30

SAGITTARIUS

6723

6388

CORONAAUSTRALIS

6541

Q

INDUS

GRUS

6281

6302

6231

Tr24

T

Alnasl

KausAustralis

Kaus Borealis

Rasalhague

Cebalrai

ECLIPTIC

Shaula

Lesath

Kaus Media

7009

M73M72

RT

3

71

M11

M26

M14

6822

6818

VR

U12

RY

RR

5962

52

SERPENSCAUDA

M22M28

M69

M25

M18M17

M16

M24Star Cloud

OmegaNebula

Eagle Nebula

M70

M54

M75

I.4776

M23

M6

6383

M7

M8

M20M21

6530LagoonNebula

TrifidNebula

BM

UY

Y

RS

XW

G

45

36

44

6572

I.4665

6633

6709

I.4756

68 59

72

7067

Albali

Sadalsuud

XR

–40°

–30°

–20°

–10°

0°

+10°

–40°

–30°

–20°

–10°

0°

+10°

17h 18h 19h 20h 21h 22h

18h 19h 20h 21h

1210

19

4

S_Sky_Guide_TEXT_3ed_03.indd 69 7/5/08 11:33:16 AM

CHArT 1221 Hours to 24 Hours rA 40 to 10 degrees Dec

This is a dull stretch of sky with few bright stars. The inter est is in the asso ci a tions of the con stel la tions. This region might be dubbed the ‘wet corner of the sky’, since many of the con stel la tions here and nearby have some thing to do with water. They include the two zodiac signs Capricornus the Sea-Goat and Aquarius the Water-Carrier (as well as the next sign to come, Pisces the Fish), and Piscis Austrinus the Southern Fish. East of Aquarius lies Cetus the Sea Monster.

Ancient people used the stars as a cal en dar. It may be that thou sands of years ago (when these con stel la tions were first named), the Sun in its yearly travels reached this part of the sky during or just before the wet season of the year. Certainly, Capricornus hosted the south ern summer sol stice (reached by the Sun around 21 December) 2000 years ago. The com pil ers of horo scopes still use Capricornus to rep re sent people born in the month com menc ing 21 December, and geog ra phers use the term ‘Tropic of Capricorn’ to link those points on Earth at which the Sun is over head at noon on that day.

Neither the Sea­Goat, the figure of a goat with a fish’s tail, nor the Water­Carrier pouring out water from an urn on his shoul der, have any bright stars. A pair of faint ish stars about 3 degrees (a couple of fingers) apart at the western end of Capricornus are dis tinc tive. Both are wide doubles. Alpha Capricornii, to the north, is one for the keen naked eye, with stars of mag ni tudes 3.6 and 4.2 sep ar ated by 6.3 minutes of arc. They are marked sep ar ately on this chart. Beta is harder to see and binoc u lars are needed. Its 3.1 and 6.1 mag ni tude com po nents lie 3.4 minutes of arc apart.

Aquarius is an ancient sign, dating back to Babylonian times, 4000 years or more ago. The stream pouring from the Water­Carrier’s urn or barrel rep re sented the time of the annual flood. N7293 (the Helix Nebula), which lies close to the south ern boun dary of Aquarius (near 22 hr 30, 21 deg.), is the closest and appar ently largest of the plan e tary nebulae. Though half the size of the Full Moon, the nebula is quite faint. Binoculars reveal it as a misty patch. Aquarius is home to two meteor showers; the Eta Aquarids of early May (peaking 6 May), asso ciated with Comet Halley, and the double-barrelled Delta Aquarids of late July and early August (peaking on July 29 and August 7).

The bright est star in the area is the first mag ni tude Fomalhaut in Piscis Austrinus. In old star pic tures Aquarius was shown pouring a stream of water into the mouth of the Southern Fish, with Fomalhaut rep re sent ing that mouth. With the three bright est stars in Grus the Crane to the south, Fomalhaut makes up a dis tinc tive and easily rec og nised tra pe zium or cross, which rides high in the south ern sky early in winter even ings.

Fomalhaut was one of the four Royal Stars of Ancient Persia, stars which marked points along the zodiac linked to the seasons. Four thou sand years ago, the Sun would have neared Fomalhaut around north ern mid winter (the sol stice then lying among the dull stars of Aquarius just to the north). The other royal stars were Aldebaran in Taurus (marking north ern spring), Regulus in Leo (north ern summer) and Antares in Scorpius (north ern autumn).

70

S_Sky_Guide_TEXT_3ed_03.indd 70 7/5/08 11:33:16 AM

71

M30

7009

M73M72

3

71

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

ECLIPTIC

PHOENIX

SAGITTARIUS

TEL

INDUS

AQUARIUS CETUS

PISCES

PEGASUS

EQUULEUS

DELPHINUS

AQL

Kitalpha

Enif

Fomalhaut

Skat

Ancha

Albali

Sadalsuud

Sadalmelik

Sadachbia

NashiraDeneb Algedi

Biham

Homam

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

SCULPTOR

PISCIS AUSTRINUS

CAPRICORNUS

MICROSCOPIUM

Alnair

I.1459

24

GRUS

55 300

7793

Ankaa

S

T

R

99 7

298

88

86

TX

XZ

30

7293Helix Nebula

M2

55

–40°

–30°

–20°

–10°

0°

+10°

–40°

–30°

–20°

–10°

0°

+10°

20h 21h 22h 23h 0h 1h

21h 22h 23h 0h

511

20

4

S_Sky_Guide_TEXT_3ed_03.indd 71 7/5/08 11:33:17 AM

CHArT 130 Hours to 3 Hours rA 0 to 55 degrees Dec

The most sig nifi cant con stel la tions in this part of the sky are a pair of zodiac signs, Pisces the Fish and Aries the Ram. Pisces, which has no bright stars, is com monly drawn as a pair of fish with their tails tied together with long strings, swim ming in oppo site direc tions. Looking north, it lies just above (south) and to the east of the Great Square of Pegasus (see Chart 20). The bright est star, in the south-east corner, marks the knot joining the two strings.

Aries, next door to the east, pos sesses two bright ish stars, close together and easily rec og nis able. The brighter of the two is Hamal. Behind the con stel la tion lies the story of the magical flying ram which rescued two chil dren from their wicked step mother, and whose Golden Fleece, hanging in a sacred grove in far away Colchis, lured Jason and the Argonauts in a per i lous quest in the years before the Trojan War. Above (south of) Aries, a pen ta gon of stars marks the head of Cetus the Sea Monster.

In our present epoch, the Sun crosses the celes tial equator going north and reaches a point among the western stars of Pisces around 21 March. The entry of the Sun into Pisces there fore marks the north ern vernal equinox (the autumn equinox for the Southern Hemisphere). Two thou sand years ago this event occurred further east, with the Sun enter ing Aries. The change since that time results from the pre ces sion of the equi noxes.

Tradition dies hard. The vernal equinox is still often called the First Point of Aries, and is marked by the old astro-log i cal symbol for Aries. The com pil ers of horo scopes con tinue to insist that Aries is the sign for people born in the month com menc ing 21 March.

The meteor shower known as the Arietids emerges from a point in the south ern part of Aries (about 10 degrees above and to the left of the Pleiades) in the first two weeks of June, peaking on 7 June.

North of (below) Aries and Pisces and the small con stel la tion Triangulum, lines of bright ish stars mark the where-abouts of Andromeda the Woman Chained. The west ern most and bright est star, Alpheratz, marks the maiden’s head and forms part of the Great Square of Pegasus (see Chart 20). Beta and Gamma Andromedae carry the line north-east towards the horizon, lying about 10 degrees apart.

The con stel la tion recalls the legend of the prin cess chained to a rock in atone ment for a boast made by her mother about her (Andromeda’s) beauty and rescued from a sea monster by Perseus. Most of the char ac ters in this tale are in the sky around about: Cetus the Sea Monster to the south (see Chart 5), and, further north, the maiden’s parents Cepheus and Cassiopeia. Her rescuer is next door on the eastern side (Chart 14).

The con stel la tion is notable for the pres ence within it of the nearest and bright est of the exter nal gal ax ies, N224, com monly called the Andromeda Galaxy or M31. This near twin of our Milky Way system lies about two million light years distant and is found about 6 degrees below and to the left of Beta Andromedae. Six times wider than the Full Moon, and with an inte grated mag ni tude of 3.5, the nebula appears as a faint smudge to the naked eye on a dark night, and is a good target for binoc u lars and small tele scopes.

Three other members of our ‘local group’ of gal ax ies lie nearby in the sky, all fainter than M31 to our eyes. N221 (M32, mag ni tude 8.2) and N205 (M110, mag ni tude 8.0) are close to M31. More prom i nent is N598 (M33, mag ni tude 5.7 and twice the size of the Full Moon), about 10 degrees to the south­east (above and to the right) in Triangulum.

The region has other sights worth looking for with binoc u lars. About 5 degrees south of Gamma Andromedae (close to the border with Triangulum) lies the open cluster N752 (diameter 50, mag ni tude 5.8). Gamma Andromedae is itself double (mag ni tudes 2.3, 4.8, yel low ish and bluish, 10 seconds apart).

72

S_Sky_Guide_TEXT_3ed_03.indd 72 7/5/08 11:33:18 AM

73

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

ANDROMEDA

CASSIOPEIA

TRIANGULUM

PERSEUS

LACERTA

CAMELOPARDALIS

TAURUS

Algenib

Alpheratz

Algol

Mirphak

Mirach

Almaak

Hamal

Sheratan

Mesartim

Menkib

Atik

Shedir

RZ

41

5

925

M76

M43

891

869884

1023 13421499

CaliforniaNebula

1528

1545

457

R

W

48

6

17

16

b1

b2

M74

M33

TV

70

147

185

752

M31

M32

M110

Andromeda Galaxy

Double Cluster

7662

7789

R

R

RR

51

7

4

ARIES

CETUS

ERIDANUS

PISCES

PEGASUS

ECLIPTIC

TX

XZ

Menkar

M77Alrescha 0°

+10°

+20°

+30°

+40°

+50°

0°

+10°

+20°

+30°

+40°

+50°

0h 1h 2h 3h

0h23h 1h 2h 3h 4h

1420

5

S_Sky_Guide_TEXT_3ed_03.indd 73 7/5/08 11:33:19 AM

CHArT 143 Hours to 6 Hours rA 0 to 55 degrees Dec

The north ern parts of this stretch of sky are filled with the stars of Perseus, the hero who rescued Andromeda, and of Auriga the Charioteer. Old star pic tures of the latter also show a goat, which is marked by the first mag ni tude star Capella (sixth in order of bright ness among the stars). The name means ‘little goat’. Though bright, this star is elusive from south ern lat i tudes; from most centres of pop u la tion it rises barely 10 degrees above the north ern horizon.

Perseus has no bright stars. It does boast the fifth mag ni tude California Nebula (N1499) (the shape gives the name), which lies near 4 hr, 36 deg. Three degrees by one, it is rated mag ni tude 5. Ten degrees to the west and a little lower in the sky is the famous eclips ing var i able star Algol (Beta Persei) that changes mag ni tude from 2 to 3.5 and back every three days. Algol, dubbed ‘the devil star’, is often shown on maps as marking the eye of the snake-haired monster Medusa, whose severed head Perseus is car ry ing. Alpha Persei, some 8 degrees further north, is sur rounded by a large, bright, open cluster (Melotte 20).

Higher in the sky lies one of the great zodiac signs, Taurus the Bull. It is com monly depicted as rushing at nearby Orion the Hunter, which lies to the south-east (above and to the right). Orion is defend ing himself with a club (see Chart 6). The Bull is among the most ancient of the star signs, dating back to at least Babylonian times 4000 years ago. Then it hosted the vernal equinox that now lies to the west in Pisces. Some sources iden tify Taurus with the Cretan Bull tamed by Hercules, others with the dis guise used by Zeus to seduce Europa, others still with the fire-breathing brazen-hoofed bulls Jason had to tame on his route to the Golden Fleece.

Though only the front half of the Bull is shown (as if it was coming out of water), Taurus has some great sights. Marking the shoul der of the Bull, and the first stars to appear as the con stel la tion rises, are the Pleiades or the Seven Sisters (M45). Four times the diam e ter of the Full Moon, this open cluster of young, hot, blue stars is a superb spec­ta cle even with the naked eye. On clear dark nights keen eyes will find eight or even ten to be naked-eye objects. Binoculars or a small tele scope will reveal 30 or more stars. The bright est is Alcyone at mag ni tude 2.9. The ear li est ref er ences to the cluster are from China more than 4000 years ago.

Following the Pleiades across the sky (its name means as much) is the red giant star Aldebaran, which appro pri ately marks the eye of the Bull. This was one of the Royal Stars of ancient Persia, along with Regulus, Antares and Fomalhaut. These stars were the markers of the seasons as they lay then.

From our point of view Aldebaran is super im posed on a more distant V-shaped star cluster known as the Hyades. (At one time, the whole cluster was called Aldebaran.) One hundred and fifty light years distant, this is the nearest of the major open clus ters. Two of the stars in the Hyades are wide doubles, easily resolved with the naked eye or with binoc u lars: Theta Tauri (mag ni tudes 3.4 and 3.8, sep ar a tion 5.6) and Sigma Tauri (mag ni tudes 4.7, 5.1, sep ar a tion 7.3).

Both the Hyades and the Pleiades have mytho log i cal asso ci a tions. In one tra di tion, they rep re sent two groups of sisters, all daugh ters of Atlas but with dif fer ent mothers. Both were placed by Zeus among the stars; the Hyades as a reward for nursing one of the god’s chil dren, the Pleiades as a pro tec tion against the amorous advances of Orion. The rising and setting of the Hyades and Pleiades were tra di tion ally asso ciated with rain.

Filling out the con stel la tion to the east are stars delin eat ing the horns of the beast, with Beta Tauri (Alnath, the ‘butting one’) making the tip of the north ern horn. Close to the other tip you can find the Crab Nebula (N1952 or M1). This nebula is the remnant of a super nova seen by Chinese astron o mers in 1056. One fifth the width of the Full Moon, it is rated mag ni tude 8.

One of the year’s lesser meteor showers, the Taurids, emerges from two points in the night sky above the Pleiades over the month fol low ing 25 October, with a peak around 7 November. It is asso ciated with Comet Enke and may produce about 12 meteors an hour.

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S_Sky_Guide_TEXT_3ed_03.indd 74 7/5/08 11:33:20 AM

75

Alnitak

V

T

8

Betelgeuse

MintakaAlnilam

Meissa1662

M78

2024

88

90

71

Bellatrix

W

32

ORION

Menkar

M77

10

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

ECLIPTIC

H y a d e s

M45Pleiades

MON

GEMINI

AURIGA

ANDROMEDA

LYNX

CAMELOPARDALIS

CAS

Alcyone

Aldebaran

Alnath

CapellaMenkalinan

Almaak

Propus

Mebsuta

1647

1746BU

HU

19,20

23 2717

37

58

7

M1Crab Nebula

M35

2169

119

M36M37

M38

2281

TV

U

1

BL

AR

UU

WW

RT

PU

R

21

TRIANGULUM

PERSEUS

TAURUS

Algol

Mirphak

Menkib

Atik

ARIES

CETUS

ERI ERI

RZ

41

5

M76

M43

1342

1499California

Nebula

1528

1545

925R

48

6

17

1023

16

b1

b2

752

51

891

W

0°

+10°

+20°

+30°

+40°

+50°

0°

+10°

+20°

+30°

+40°

+50°

3h 4h 5h 6h

3h2h 4h 5h 6h 7h

1513

6

S_Sky_Guide_TEXT_3ed_03.indd 75 7/5/08 11:33:22 AM

CHArT 156 Hours to 9 Hours rA 0 to 55 degrees Dec

The Milky Way cuts through the south­west corner of this area of night sky, cross ing among other things the feet of Gemini the Heavenly Twins. The Twins’ feet are close to the head of Orion the Hunter, most of which lies on the other side of the Milky Way. At the north­eastern end of this roughly rec tan gu lar con stel la tion, the heads of the pair are marked by the bright stars Castor and Pollux. Like so many star groups, the Twins are upside down when viewed from the Southern Hemisphere. Though listed as Alpha Geminorum, Castor is cur rently fainter than Pollux, indi cat ing that it has waned or Pollux waxed in bright ness in recent cen tu ries.

Castor looks like a single star to the unaided eye, but it is actu ally six stars in close asso ci a tion, all born long ago from the same cloud of gas. A small tele scope will divide Castor in two. A pair of white stars, mag ni tudes 1.9 and 2.9, lie only 4 seconds of arc apart, and circle each other every 400 years. Castor was in fact the first pair of stars known to be orbit ing each other, noted by William Herschel in 1803. Each com po nent star is a very close double, and other stars also form part of the action.

The star names are also the names of the heroes. In Greek legend, Castor and Pollux were sons of Leda, Queen of Sparta, and broth ers to Helen of Troy. Pollux (or Polydeuces), being the son of Zeus (who seduced Leda in the guise of a swan), was immor tal and was famed as a boxer. Castor, a famous horse man, was the son of a mortal. Both were voy ag ers with Jason on the Argo in search of the Golden Fleece.

At the western end of Gemini, at 6 hours of right ascen sion, the eclip tic reaches its maximum dis tance north of the celes tial equator. This point on the celes tial sphere there fore marks the (north ern) summer sol stice, reached by the Sun around 21 June. This is the short est day of the year (winter sol stice) south of the equator. 

The Geminids, one of the con sis tent per form ers among the meteor showers, emerges from the night sky close to Castor from 7 to 15 December, with a peak around 13 December. Under the right con di tions, you may see 50 meteors an hour. Gemini too boasts a bright ish cluster, lying in front of the Milky Way at the south­western end of the con stel­la tion (near 6 hr 10, 24 deg). N2168 (M35) is the size of the Full Moon and is rated at mag ni tude 5.

East of Gemini lies another zodiac con stel la tion, Cancer the Crab. Cancer is bereft of bright or even bright ish stars. Legends suggest that such was its fate, having been crushed as pun ish ment for biting the heel of Hercules as he was bat tling with the Hydra. Such stars as there are make up a three-pointed figure centred on Gamma Canceri that lies on the ecliptic.

Cancer’s main offer ing to sky watch ers is Praesepe or the Beehive Cluster (N2632, M44), which lies a few degrees north­west of Gamma Canceri. At mag ni tude 3 and diam e ter three times that of the Full Moon, it is no match for the Pleiades, but is well worth a look through binoc u lars, which will easily reveal 15 or so stars (Galileo was the first to do this). Lying only 450 light years away, the Beehive is close as open clus ters go. The old name for the Beehive is ‘the Manger’, which served as food for a pair of donkeys. These are marked by the two nearest stars, Gamma and Delta, which bear formal names meaning the ‘the north ern and south ern donkeys’.

A small cluster (N2682), still worth a Messier number (M67), lies south of (above) the Beehive, a few degrees west of Alpha Canceri.

Two thou sand years ago, the summer sol stice now found in Gemini lay in Cancer. This fact per sists in the name ‘Tropic of Cancer’ for the imag i nary line around the Earth linking all loca tions at which the Sun is over head at noon on 21 June. Consistency would seem to require a change in name to ‘Tropic of Gemini’, but that is now unlikely. In 600 years it would need to be changed again.

Monoceros, Canis Minor and Hydra border Cancer and Gemini to the south. To the north we find some faint stars of Auriga and Lynx, and a sniff of Ursa Major the Great Bear.

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77

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

ECLIPTIC

Alnath

Alhena

Propus

Castor

Pollux

Capella

Menkalinan

Mebsuta

MekbudaWasat

Alterf

Talitha

2392

BQ

R

30

6

RR

15

M44

Praesepe

R

X

2683

2903

2841

RS

R

31

38

10 UMa

10

15

26

ORION

MONOCEROS

LEO

CANCER

2301

CANIS MINOR

Gomeisa

BC14

Procyon

AcubensM67

HYDRA

TAURUS

AURIGA

CAM CAM

LYNX

PERSEUS

LEO MINOR

URSA MAJOR

GEMINI

10

Alnilam

Meissa

Betelgeuse

M78

2024Alnitak

I.434HorseheadNebula

2244

2237Rosette Nebula

2264 S

T

8

13

7

M1Crab Nebula

M35

119

2281

TVU

1

2169BL

M36

M37

M38 UU

WW

21

RT

PU

1545

AR

Asellus Australis

Asellus Borealis

0°

+10°

+20°

+30°

+40°

+50°

0°

+10°

+20°

+30°

+40°

+50°

6h 7h 8h 9h

6h5h 7h 8h 9h 10h

1614

7

S_Sky_Guide_TEXT_3ed_03.indd 77 7/5/08 11:33:24 AM

CHArT 169 Hours to 12 Hours rA 0 to 55 degrees Dec

This stretch of sky belongs to Leo the Lion. Allowing for the fact that the con stel la tion is upside-down to Southern Hemisphere viewers, not a lot of imag i na tion is needed to discern a lion among the stars. A hooked line of stars at the western end of the group pro files the beast’s head and neck, ending with the first mag ni tude star Regulus to mark a front paw (or perhaps the lion’s heart). A tri an gle of stars two fists width to the east marks the rump and tail. The bright est of those stars is Denebola, that name coming from the Greek for ‘tail’.

Leo is gen er ally held to rep re sent the Nemean Lion, slain by the mighty Hercules of Greek and Roman legend as one of his Twelve Labours, but there are, as usual, other pos sibil ities. The asso ci a tion of a lion with these stars is much older. Regulus was one of the Royal Stars of Persia, along with Aldebaran, Antares and Fomalhaut, since 4000 years ago it was home to the summer sol stice now located in Gemini. Links between the Sun and Leo are there fore very ancient and may explain the common and long-stand ing link between the lion and royalty (such as the lion being the ‘king of beasts’). The name Regulus is derived from a word for ‘king’.

Regulus lies just north of the eclip tic. As a result, it is com monly approached, or even occulted, by a planet. A close approach by Mars or Jupiter can be a spec tac u lar sight.

Gamma Leonis or Algieba, the second bright est star in the hook, is a double, with a pair of yellow stars rated at mag ni tudes 2.3 and 3.5. With a sep ar a tion of only 4 seconds of arc, a small tele scope is needed to split them. R Leonis, 5 degrees west of Regulus, is a Mira­type var i able, swing ing between mag ni tudes 4.4 and 11.3 every 312 days.

Leo is the site of one of the more erratic meteor showers; the Leonids emerge from near Gamma Leonis around 15 to 20 November, peaking around 17 November, and have been noted for at least 1000 years. It is asso ciated with Comet Temple 1 that last came by in 1866. The number of meteors increases to a peak every 33 years (1999 was a peak year).

Beneath the belly of the Lion (that is, above it as it stands in the sky) lie a number of exter nal gal ax ies, out li ers of the Virgo Cluster (see text to Chart 9). None is brighter than the eighth mag ni tude. The easiest to find are N3623 and N3627 (M65 and M66), which good binoc u lars will pick up as fuzzy spots on a dark night (near 11 hr 20, 12 deg.). A 100 mm tele scope is needed to reveal their shapes.

North of Leo lies the much smaller Leo Minor and then the stars of the major Northern Hemisphere con stel la tion Ursa Major the Great Bear. These stars rise only 10 or 20 degrees at most above the north ern horizon and the con stel la tion is not easy to discern.

78

S_Sky_Guide_TEXT_3ed_03.indd 78 7/5/08 11:33:24 AM

79

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

M97Owl Nebula

M108

M109

3184

CG

W

VIRGO

COMABERENICES

CANIS VENATICI

LEO MINOR

LYNXURSA MAJOR

UMA

Alterf

Rasalas

Adhafera

AlgiebaZosma

Chertan Denebola

Chara

Cor Carola

Asellus Australis

Asellus Borealis

Talitha

Merak

Phad

Tania Borealis

Tania Australis

Alula Borealis

Alula Australis

46

21

M105

M96M95

3348

R

54

60

M106

4449

4490

M94ST

Y

TU

4631

4214

M86

4435/38

4216

M99M98

M100

M85

4494

4565

4559

M88

M87M84

M65 M66

3628

Mel 111

93

SEXTANS

ECLIPTIC

HYDRA

3521

LEO

Regulus

VY

31

M61

4365

4371

Zaniah

Zavijava

CANCER

M67 Acubens

X

2683

2841

31

10 UMa

15

R

3810

RS

26

21

M44Praesepe

2903

3344

0°

+10°

+20°

+30°

+40°

+50°

0°

+10°

+20°

+30°

+40°

+50°

9h 10h 11h 12h

9h8h 10h 11h 12h 13h

1715

8

S_Sky_Guide_TEXT_3ed_03.indd 79 7/5/08 11:33:26 AM

CHArT 1712 Hours to 15 Hours rA 0 to 45 degrees Dec

This area of sky pos sesses few bright stars other than Arcturus in Bootes. It is remote from the Milky Way, with the North Galactic Pole (NGP) to be found within the con stel la tion Coma Berenices (near 12 hr 50, 27 deg.). The eclip tic passes to the south, with Virgo the nearest zodiac con stel la tion.

Coma Berenices (Berenice’s Hair) and Canes Venatici (The Hunting Dogs) are largish but dull con stel la tions. They are notable mostly for the numbers of gal ax ies within their borders. These con tinue the cluster centred in the north ern regions of Virgo, a cluster com monly called the Virgo Cluster (see Chart 9). This con tains many hun dreds of spiral and ellip ti cal gal ax ies, located at dis tances esti mated at 40 to 60 million light years.

Some of these may be glimpsed as fuzzy points of light in binoc u lars and small tele scopes. The best start ing point is with the mag ni tude 8.4 galaxy N4472 (M49) in Virgo (near 12 hr 30, 8 degrees). Many gal ax ies of mag ni tude 9 and fainter are scat tered over the sky about 5 degrees north of M49, across the Virgo/Coma Berenices border. A few more lie at the north ern end of Coma near the galac tic pole. More gal ax ies still are widely scat tered in Canes Venatici. Five degrees west of the Pole and near Gamma Coma Berenices we find the open cluster Melotte 111 (the Coma Cluster), which is both bright (inte grated mag ni tude 1.8) and large (almost 5 degrees across).

Bootes the Herdsman, lying to the east of the two star groups men tioned earlier, is dom i nated by the orange giant star Arcturus, fourth bright est in the sky (after Sirius, Canopus and Alpha Centauri). It weighs almost the same as our Sun, but is larger, brighter and cooler, all char ac ter is tics of a Sun-like star in old age.

From Arcturus, marking the head of Bootes, an elon gated pen ta gon of stars runs north-east towards Ursa Major the Great Bear. The two con stel la tions can be linked in several ways. Bootes as Herdsman drives the Great Bear around the North Pole. In images in which the stars of Ursa Major become a plough or a wagon, Bootes is the Ploughman or Waggoner. From Arcturus (or more from ‘arktos’, the Greek for ‘bear’) we get our word ‘arctic’, for the region where the two bears (major and minor) are high in the night sky.

The Quadrantids meteor shower, gen er ally the year’s bright est, has its radiant in the north ern part of Bootes, peaking around 3 January. The name comes from the now aban doned con stel la tion Quadrans Muralis  (the Wall Quadrant), which used to occupy this part of the sky.

For hunters after glob u lar clus ters, binoc u lars will reveal M3 (N5272) in the south ern realm of Canes Venatici (near 13 hr 40, 28 deg.), at mag ni tude 6.

80

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81

VIRGO

LIBRA

LEO

BOOTES

SERPENSCAPUT

M5

109110

4753

Vindemiatrix

5248M49

4636

45264535

R

M61

4365

M60M59

M584371

PorrimaZaniah

Zavijava

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

NGP

URSA MAJOR

CANES VENATICI

COMABERENICES

CORONABOREALIS

HERCULES

DRACO

Denebola

Cor Caroli

Chara

ArcturusMuphrid

Izar

Seginus

Alkalurops

Nekkar

Alphekka

Nusakan

Alula Borealis

Alula Australis

Phad

Megrez

Alioth

Mizar Alcor

Alkaid

M53

M64 FS

R

M10180

W

i

5866

X

A

M97Owl Nebula

M109

M106

4449

M94 M63

M3

M51Whirlpool Galaxy

5195

Y

TUST

4631

4214

4435/384216

M99M98

M100

M85

M88

M90

M91

M89

93

4494 4565 4725

4559

Mel 111

M86M87

M84

0°

+10°

+20°

+30°

+40°

+50°

0°

+10°

+20°

+30°

+40°

+50°

12h 13h 14h 15h

12h11h 13h 14h 15h 16h

1816

9

S_Sky_Guide_TEXT_3ed_03.indd 81 7/5/08 11:33:27 AM

CHArT 1815 Hours to 18 Hours rA 0 to 55 degrees Dec

There are no bright stars in this corner of the sky and no strik ing con stel la tions. Much of the sky is taken up with the scat tered stars of Hercules, per former of the famous Twelve Labours and voyager on the Argo with Jason in the quest for the Golden Fleece. On old star charts, Hercules is often shown with club and lion skin, kneel ing with his foot on the head of Draco the Dragon, a far north ern con stel la tion. With a little imag i na tion, the observer can recover the image of a man with great arms and legs from the scat tered stars.

Interestingly, for Southern Hemisphere viewers, Hercules is the right way up, unlike Ophiuchus just to the south (see Chart 10), which is head down for us. Its bright est star, Rasalgethi (‘the Kneeler’s Head’) lies at the south ern (upper) end of the con stel la tion, within a few degrees of Rasalhague (‘the Serpent-Charmers Head’) in Ophiuchus. This is an indi ca tion of the lat i tude from which those who formed the con stel la tions viewed the sky.

Hercules is cer tainly big, in the top half dozen con stel la tions for size. These stars have been formed into the image of a hero since Babylonian times, 4000 or more years ago. In giving the stars to Hercules, the Greeks were merely con-tin u ing an old tra di tion.

The best binoc u lar or small tele scope sight here is among the western stars of Hercules, a few degrees above Eta. N6205 (M13) is the bright est glob u lar cluster in the north ern sky, though at mag ni tude 5.7 and diam e ter 17 minutes of arc, it is no match for Omega Centauri or 47 Tucanae in the south. M13 con tains some 300,000 stars in a space 100 light years across and lies about 22,000 light years away.

The rest of the sky here con tains the small con stel la tion Corona Borealis the Northern Crown, with an inter est ing arc of small stars; the north ern stars of Serpens Caput (the head of the serpent being wres tled by Ophiuchus further south); and a bit of Bootes. In Ophiuchus itself, you can find I4665 about 10 degrees south of Alpha Ophiuchi (Rasalhague). This is a loose cluster worth seeking with binoc u lars, being mag ni tude 4.2 and twice the diam e ter of the Full Moon.

One item of inter est in this region is the loca tion of the so-called Apex of the Sun’s Motion, the point in the heavens towards which the Sun appears to be moving as it circles the Galaxy. Measurements of the appar ent move ments of the stars suggest that this lies in the eastern part of Hercules, close to its boun dary with Lyra the Harp.

82

S_Sky_Guide_TEXT_3ed_03.indd 82 7/5/08 11:33:28 AM

83

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

6210

I.4593

LQ

U

R

s

LIBRA

HERCULES

CORONA BOREALIS

LYRA

CYGNUSDRACO

URSAMAJOR

CANESVENATICI

AlkaidEtamin

Rastaban

Grumium

Alrakis

Vega

Sheliak

S

M13

M92

g

16, 17

95102

109

u

cM57

RingNebula

XY

OP

R

R

OPHIUCHUS

SERPENSCAUDA

SERPENS CAPUT

HERCULES

VIRGO

BOOTES

Unukalhai

6572 6633

68

72

7067

Rasalhague

Rasalgethi

Kornephoros

I.4665

Cebalrai

U

M5109 110

Izar

Seginus

Alkalurops

Nekkar

Alphekka

Nusakan

M101

i

5866

A

W

X

0°

+10°

+20°

+30°

+40°

+50°

0°

+10°

+20°

+30°

+40°

+50°

15h 16h 17h 18h

15h14h 16h 17h 18h 19h

1917

10

S_Sky_Guide_TEXT_3ed_03.indd 83 7/5/08 11:33:29 AM

CHArT 1918 Hours to 21 Hours rA 0 to 55 degrees Dec

This is a spec tac u lar stretch of sky, crossed by the Milky Way from south­west to north­east, and home to the three bright stars of the Winter Triangle (Deneb, Vega, Altair), so called because they are most prom i nent on early even ings in winter in the South ern Hemi sphere (it is the Summer Triangle north of the equator). On the western side we find frag ments of the heroes Hercules and Ophiuchus. A few small, dim con stel la tions (Sagitta the Arrow, Vulpecula the Fox and Delphinus the Dolphin) take up further space. The ‘big three’ on the other hand are Lyra the Harp, Cygnus the Swan and Aquila the Eagle.

For all its length in this region, the Milky Way appears divided, due to the pres ence of a band of dust com monly found in the spiral arms of gal ax ies. The con stel la tion Cygnus is the form of a cross that evokes a swan flying south along the Milky Way, though the con stel la tion has some times been drawn as a hen. As a swan, its pos sible asso ci a tions include Leda, seduced by Zeus in the guise of a swan, so giving birth to the hero Pollux, one of the hea venly twins.

The long bar of the Northern Cross is made up of Beta, Eta, Gamma and Alpha Cygni, with Delta, Gamma and Epsilon as the cross bar. Deneb (‘the tail’) is the first mag ni tude star that brings up the rear of the swan. With dec li na­tion 45 degrees, Deneb remains low in the north ern sky for most centres of pop u la tion south of the equator. Of the 20 or so bright est stars as seen from Earth, Deneb is the most distant (nearly 2000 light years), and the star with the great est intrin sic bright ness. An abso lute mag ni tude of 8 makes it some 25,000 times brighter than our Sun.

Several bright nebulae show up against the back ground stars, notably the appro pri ately shaped North America Nebula (N7000), 5 degrees east of Deneb. This is rated mag ni tude 4 and covers more than 12 times the area of the Full Moon. As with Deneb, finding this nebula needs a clear north ern horizon. The much larger but fainter and more elusive Veil Nebula (N6960) is some 15 degrees south of Deneb. This nebula, only mag ni tude 7 but 7 Moon diam e ters wide, is a super nova remnant.

To the west and a little higher in the sky lies Lyra the Harp, with one strik ing star Vega (fifth in bright ness in the sky). Imagination is cer tainly needed here to find a harp among these stars! A degree or so away from Vega on the lower right, Epsilon Lyrae (a ‘double double’), is a good test for keen eyes. Its two fifth mag ni tude com po nents lie over 3 minutes of arc apart. Binoculars will confirm this, and a small tele scope will reveal that each star is itself a double.

Beta Lyrae, about 7 degrees south-east of Vega, is another star with sur prises. It is a double (yellow-white and blue, first and eighth mag ni tudes) easily split in small tele scopes. But the bright primary is an eclips ing var i able, shift ing from mag ni tude 3.3 to 4.3 every 13 days. Gamma Lyrae, a con stant mag ni tude 3.2 nearby, can be used for com par i son.

One of the more elusive sights of Lyra is the well-known Ring Nebula (N6720, M57), a plan e tary nebula lying between Beta and Gamma. At mag ni tude 8.8 and little more than 1 minute of arc across, it is no easy target. A large tele scope is needed to reveal its ring-like shape.

Smaller but brighter than the Ring Nebula is N6853 (the Dumbbell Nebula, M27), in front of the Milky Way in Vulpecula (near 20 hr, 23 deg.). With mag ni tude 7.3, it is as bright as any plan e tary nebula in the sky, being only 1000 light years away. About 10 degrees south-west of the Dumbbell Nebula on the border with Sagitta is the dis tinc-tive open cluster dubbed the Coat-Hanger, more for mally known as Collinder 399.

Completing the Winter Triangle is Altair, the bright est star in Aquila the Eagle. It lies much higher in the sky than Deneb and Vega and, unlike them, it has another bright ish star (Gamma Aquilae) only a few degrees away. The pair form a dis tinc tive group ing.

84

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85

OPHIUCHUS

SERPENSCAUDA

71

EQUULEUS

Kitalpha

DELPHINUS

Alya

Tarazed

Altair

Alshain

6709

6572 6633

I.4756

59

72

X

R

Rasalhague

Cebalrai

I.4665

68

7067

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

M71

M27Dumbbell Nebula

Coll 399

UU

U

S

SU

13

1

HERCULES

LYRA

CYGNUS

AQUILA

AQUARIUS

SAGITTA

VULPECULA

PEGASUS

PEG

DRACOLACERTA

CEPHEUSCEP

Rastaban

Etamin

Alrakis

Vega

Sheliak

Sulafat

Grumium

Albireo

Deneb

Sadr

FF

M56

6811

6826

AF

33

M15

6882/85

23 31

2

1

Veil Nebula

69606992-95

6940

T

T

X

5241

39

7027

M39

7000

I.5067-70

M29

6871

6910

North America Nebula

Pelican Nebula

7243

DT

AR

P

63

61

4

5

2

W

95

102109

110

111

113

u

c

RingNebulaM57

XY

R

R

RT

M92 OP

0°

+10°

+20°

+30°

+40°

+50°

0°

+10°

+20°

+30°

+40°

+50°

18h 19h 20h 21h

18h17h 19h 20h 21h 22h

20

18

11

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CHArT 2021 Hours to 24 Hours rA 0 to 55 degrees Dec

Though not one of the more spec tac u lar stretches of night sky, there are many things of inter est here. The most obvious feature is a rough square of mod er ately bright stars known as the Great Square of Pegasus. The square, lying to the east of Cygnus the Swan, is large, some 15 degrees or one and a half fists wide in each direc tion. Strictly speak ing, only three of the four stars belong to Pegasus the Flying Horse. The north-east star (on the lower right) is now a days given to the con stel la tion of Andromeda the Chained Maiden, in which it marks the head of the prin cess (see Chart 13). However, its name Alpheratz (‘the navel of the horse’) indi cates its former asso ci a tion.

Most people asso ciate Pegasus with Perseus, the rescuer of Andromeda. However, legend gives the honour of riding Pegasus to Bellerophon, the hero noted for his fatal bold ness in seeking to ride to heaven. The role of Perseus was in bring ing the winged steed into being, since Pegasus was created from the blood of the mon strous Medusa, slain by Perseus, falling into the sea.

Unlike most north ern con stel la tions, Pegasus is upright when viewed from our part of the world. What is more, the stars do, with little imag i na tion, suggest the front portion of a horse gal lop ing (or flying) to the west. From the top left­hand corner of the square a curved line of stars traces the horse’s head and neck. This begins with Alpha Pegasi (Markab for ‘saddle’) and ends at the orange super giant star Enif (‘nose’). The latter is the brightest in the constel lation, even though it is labelled only Epsilon Pegasi. Lines of stars from the lower left-hand star (Beta Pegasi or Scheat, meaning ‘upper arm’) mark out the horse’s front legs.

A few degrees north-west of Enif lies the glob u lar cluster M15, 30,000 light years away. At mag ni tude 6.0 and diam-e ter 12 minutes of arc, this is larger and brighter than many. It shows up as a fuzzy patch in binoc u lars, and small tele scopes show its bright core, though they cannot resolve indi vid ual stars.

The rest of the sky here is not mem or able; frag ments and edges of Andromeda and other nearby con stel la tions, and the insig nifi cant con stel la tions Equuleus the Colt or Foal and Lacerta the Lizard. The nearest zodiac sign is Pisces the Fish, lying south­east (that is, above and to the right) of the Great Square. 

86

S_Sky_Guide_TEXT_3ed_03.indd 86 7/5/08 11:33:32 AM

87

DEEPSKY OBJECTS

Open star clusters Globular star clusters Planetary Nebulae Diffuse nebulae Galaxies

MAGNITUDES

6 5 4 3 12 0 brighter Double stars Variable stars

ECLIPTIC

CYGNUS

VULPECULA

CEPHEUS

CASSIOPEIA

LACERTA

ANDROMEDA

PSC

PER

Alpheratz

Markab

Algenib

Scheat

Matar

Sadalbari

7331

1

611

71

PISCES

PEGASUS

DELPHINUS

AQL

EQUULEUS

Kitalpha

XZ

Enif

Homam

M2Sadalmelik

Sadachbia

Biham

55

70

TX

Deneb

Sadr

TV

M31

M32M110

AndromedaGalaxy

7789

R

R

4 7

147185

7662

AQUARIUS

6826

M15

U

2

1

9

Veil Nebula6960

6992-95

6940

31

T

23

5241

39

7027

7000

6910

North America Nebula

I.5067-70Pelican Nebula

7243

AR

RW

M29

6871

P

63

61

5

2

T

DT

X

M39

W

R

RT

0°

+10°

+20°

+30°

+40°

+50°

0°

+10°

+20°

+30°

+40°

+50°

21h 22h 23h 24h

21h20h 22h 23h 0h 1h

1319

12

S_Sky_Guide_TEXT_3ed_03.indd 87 7/5/08 11:33:34 AM

88

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89

Helping the eye

References are made in this book to the use of binoc u lars or a small tele scope to improve the view of the night sky. Such instru ments do several things.•   They collect more light than does the naked eye (they have

a greater light grasp) and so enable the user to see fainter and more distant objects.

•   They magnify objects, making them seem larger.•   They can see finer detail (that  is,  they have greater reso­

lution).An ordi nary pair of binoc u lars would be rated 10 by 50, which means mag nifi ca tion 10  and with  lenses 50 mm  in diam e ter.  Such  binoc u lars  will  magnify  objects  10  times, which is about the highest useful mag nifi ca tion. Higher mag­nifi ca tions amplify the inev i ta ble shaking of hand­held binoc­u lars to an unac cept able degree.

More impor tantly, the 50 mm lenses will collect 50 times as much light as the unaided eye, making visible stars down to  mag ni tude  10  or  11. This  was  about  the  light  grasp  of Galileo’s first tele scope, though it mag nified 30 times. With it, Galileo saw the moun tains of the Moon, broke the Milky Way up into stars, con firmed the phases of Venus and dis cov ered the moons of Jupiter. The brighter of the nebulae, both light and dark, will show up well with binoc u lars and you can sep­ar ate many double stars.

As for res o lu tion, binoc u lars will discern details two or three arc seconds across, pro vided seeing con di tions are reason  ably  steady.  This  com pares  with  the  15  or  20  arc seconds achiev able with the eye alone. Three arc seconds is about  1/600th  the  appar ent  diam e ter  of  the  Full  Moon, which means an object about 6 km across at the dis tance of the Moon.

The main problem with binoc u lars is holding them steady. Rest your arms on some thing, like the top of a fence or the arms of a deck chair. Or lie on your back on a rug.

As with naked­eye viewing, the darker the sky the better. Avoid moon lit nights if pos sible. Avoid street lights and house lights. Get away from the glare of the city to the bush or a beach or even a large sport ing field. And give your eyes time to become dark­adapted. Half an hour makes a great dif fer­ence, and the longer you stay out the more you will see.

If you want some light to read the maps in this book when you are under the stars, put red cel lo phane over your torch, or use a torch with an almost­flat battery, so that it gives a dim reddish light. Red light does not upset night vision.

On to a telescope

The next step up is to a small (or small ish) tele scope, either a refrac tor (with a large lens at the front to collect the light) or a reflec tor (with a mirror at the lower end). Buying a tele­scope is a complex matter and it is best to take expert advice at an astro nom i cal supply store.

For  a  certain  aper ture,  a  refrac tor  will  in  general  give  a brighter,  clearer  image,  but  a  reflec tor  will  be  notice ably cheaper. Above  about  80  mm  aper ture,  refrac tors  become very  expen sive,  but  reflec tors  to  200  or  300  mm,  or  even more, are quite afford able.

A 200 mm tele scope will collect over one thou sand times as much light as the naked eye and will reveal stars down to the four teenth mag ni tude. That light grasp will reveal even the elusive planet Pluto.

Appendix A: Using binoculars and telescopes

S_Sky_Guide_TEXT_3ed_04.indd 89 7/5/08 11:33:57 AM

 90

makes it generally unmistakable, information is not provided regarding its position on the zodiac. However, the table shows whether Venus is a morning star (visible before sunrise in the east) or an evening star (visible after sunset in the west). It also gives the date of its maximum elongation east (greatest height above the sunset) and its maximum elongation west (greatest height above the sunrise). Between these two dates, the table shows when the planet is in conjunction with the Sun (at which time the planet cannot be seen). Inferior con­junction marks the transition from evening star to morning star, superior conjunction marks the reverse transition.

The  final  column  of  the  table  provides  information  on conjunctions between the four planets listed, that is, the dates when the planets come close together in the sky (to be more precise, the dates on which they reach the same right ascen­sion). While all of the conjunctions listed will occur, not all will be readily visible (to the naked eye at least). Some will occur when the planets involved are positioned in the morning sky before sunrise, rather than in the more­conven­ient­to­view  evening  sky;  others  will  take  place  when  the planets lie too close to be Sun to be visible.

The following table provides information on the positions of four of the five naked­eye planets and their relationships with the zodiac constellations, the Sun and each other over the years 2008 to 2017. The positions given are for the period around the start of each month.

Most of the information in the table refers to the exterior planets (Mars, Jupiter and Saturn), the orbits of which lie outside that of the Earth. The table indicates in which zodiac constellation the planet can be found around the start of each month, the months in which it is retrograding (moving to the west), and the dates on which the planet comes into opposi­tion (directly opposite the Sun in the sky and therefore cross­ing the meridian at midnight) and reaches conjunction (passing behind the Sun and therefore undetectable) with the Sun.

No information is supplied regarding the planet Mercury. Mercury moves so quickly against the background of the stars that information provided once a month is of little value. Mercury is also relatively faint and hard to detect.

Somewhat similar considerations apply to Venus. Because its movement is relatively rapid, and because its brilliance

 90

Appendix B: Planet positions

S_Sky_Guide_TEXT_3ed_04.indd 90 7/5/08 11:33:58 AM

 91

Tabl

e 5.

Pla

net

posi

tion

s 20

08–2

017

Plan

et p

osit

ions

200

8

Mon

thVe

nus

Mar

sJu

pite

rS

atur

nCo

njun

ctio

ns

Janu

ary

Mor

ning

Taur

us R

Sagi

ttar

ius

Leo

RFe

brua

ryM

orni

ngTa

urus

 RSa

gitt

ariu

sLe

o R

 Opp

 24

Venu

s/Ju

pite

r 01

Mar

chM

orni

ngTa

urus

 RSa

gitt

ariu

sLe

o R

Apr

ilM

orni

ngG

emin

iSa

gitt

ariu

sLe

o R

May

Mor

ning

Gem

ini

Sagi

ttar

ius

Leo

RJu

neSu

p C

onj 0

9C

ance

rSa

gitt

ariu

s R

Leo

July

Even

ing

Leo

Sagi

ttar

ius 

R O

pp 0

9Le

oM

ars/

Satu

rn 1

1A

ugus

tEv

enin

gLe

oSa

gitt

ariu

s R

Leo

Venu

s/Sa

turn

 13

Sept

embe

rEv

enin

gV

irgo

Sagi

ttar

ius

RC

onj S

un 0

4Ve

nus/

Mar

s 11

Oct

ober

Even

ing

Vir

goSa

gitt

ariu

sLe

oN

ovem

ber

Even

ing

Libr

a Sa

gitt

ariu

sLe

oD

ecem

ber

Even

ing

Con

j Sun

 05

Sagi

ttar

ius

Leo

Venu

s/Ju

pite

r 01

Plan

et p

osit

ions

200

9

Mon

thVe

nus

Mar

sJu

pite

rS

atur

nCo

njun

ctio

ns

Janu

ary

Max

. Elo

ng E

ast 1

4Sa

gitt

ariu

sC

onj S

un 2

4Le

o R

Febr

uary

Even

ing

Sagi

ttar

ius

Cap

rico

rnus

Leo

RM

ars/

Jupi

ter 

17M

arch

Inf 

Con

j 27

Cap

rico

rnus

Cap

rico

rnus

Leo 

R O

pp 0

8A

pril

Mor

ning

Aqu

ariu

sC

apri

corn

usLe

o R

Venu

s/M

ars 

18M

ayM

orni

ngPi

sces

Cap

rico

rnus

Leo

RJu

neM

ax. E

long

 Wes

t 05

Pisc

esC

apri

corn

usLe

oVe

nus/

Mar

s 19

July

Mor

ning

Ari

esC

apri

corn

us R

Leo

Aug

ust

Mor

ning

Taur

usC

apri

corn

us R

 Opp

 14

Leo

Sept

embe

rM

orni

ngG

emin

iC

apri

corn

us R

Con

j Sun

 17

Oct

ober

Mor

ning

Gem

ini

Cap

rico

rnus

RLe

oVe

nus/

Satu

rn 1

3N

ovem

ber

Mor

ning

Can

cer

Cap

rico

rnus

Leo

Dec

embe

rM

orni

ngC

ance

r C

apri

corn

usLe

o

S_Sky_Guide_TEXT_3ed_04.indd 91 7/5/08 11:33:58 AM

 92

Plan

et p

osit

ions

201

0

Mon

thVe

nus

Mar

sJu

pite

rS

atur

nCo

njun

ctio

ns

Janu

ary

Mor

ning

Can

cer 

R O

pp 2

9C

apri

corn

usV

irgo

Febr

uary

Sup 

Con

j 11

Can

cer

RC

onj S

un 2

8V

irgo

 RVe

nus/

Jupi

ter 

16M

arch

Even

ing

Can

cer

RA

quar

ius

Vir

go R

 Opp

 22

Apr

il Ev

enin

g C

ance

rA

quar

ius

Vir

go R

May

Even

ing

Can

cer

Aqu

ariu

sV

irgo

 RJu

neEv

enin

g C

ance

rA

quar

ius

Vir

go R

July

Even

ing

Leo

Pisc

esV

irgo

Aug

ust

Max

. Elo

ng E

ast 2

0V

irgo

Pisc

esV

irgo

Mar

s/Sa

turn

 01

Venu

s/Sa

turn

 10

Venu

s/M

ars 

23Se

ptem

ber

Even

ing

Vir

goPi

sces

 R O

pp 2

1V

irgo

Venu

s/M

ars 

29O

ctob

erIn

f C

onj 2

9Li

bra

Aqu

ariu

s R

Con

j Sun

 01

Nov

embe

r M

orni

ngSc

orpi

usA

quar

ius

RV

irgo

Dec

embe

r M

orni

ngSc

orpi

usA

quar

ius

RV

irgo

Plan

et p

osit

ions

201

1

Mon

thVe

nus

Mar

sJu

pite

rS

atur

nCo

njun

ctio

ns

Janu

ary

Max

. Elo

ng W

est 0

8Sa

gitt

ariu

sA

quar

ius

Vir

goFe

brua

ryM

orni

ngC

onj S

un 0

4Pi

sces

Vir

go R

Mar

chM

orni

ngA

quar

ius

Pisc

esV

irgo

 RA

pril

Mor

ning

Aqu

ariu

sC

onj S

un 0

6V

irgo

 R O

pp 0

3M

ayM

orni

ngPi

sces

Pisc

esV

irgo

 RM

ars/

Jupi

ter 

01Ve

nus/

Jupi

ter 

11Ve

nus/

Mar

s 22

June

M

orni

ngA

ries

Pisc

esV

irgo

 RJu

lyM

orni

ngTa

urus

Ari

esV

irgo

Aug

ust

Sup 

Con

j 16 

Taur

usA

ries

Vir

goSe

ptem

ber

Even

ing

Gem

ini

Ari

esV

irgo

Venu

s/Sa

turn

 30

Oct

ober

Even

ing

Can

cer

Ari

es R

 Opp

 29

Con

j Sun

 13

Nov

embe

r Ev

enin

gC

ance

rA

ries

RV

irgo

Dec

embe

r Ev

enin

gLe

oA

ries

RV

irgo

S_Sky_Guide_TEXT_3ed_04.indd 92 7/5/08 11:33:59 AM

 93

Plan

et p

osit

ions

201

2

Mon

thVe

nus

Mar

sJu

pite

rS

atur

nCo

njun

ctio

ns

Janu

ary

Even

ing

Leo

Ari

es R

Vir

goFe

brua

ryEv

enin

gLe

o R

Ari

esV

irgo

 RM

arch

Max

. Elo

ng E

ast 2

7Le

o R

 Opp

 03

Ari

esV

irgo

 RVe

nus/

Jupi

ter 

15A

pril

Even

ing

Leo

RA

ries

Vir

go R

 Opp

 15

May

Even

ing

Leo

RC

onj S

un 1

3V

irgo

 RJu

neIn

f C

onj 0

6Le

oTa

urus

Vir

go R

July

Mor

ning

Leo

Taur

usV

irgo

Aug

ust

Max

. Elo

ng W

est 2

6V

irgo

Taur

usV

irgo

Mar

s/Sa

turn

 17

Sept

embe

rM

orni

ngLi

bra

Taur

usV

irgo

Oct

ober

Mor

ning

Libr

aTa

urus

Con

j Sun

 25

Nov

embe

rM

orni

ngSc

orpi

usTa

urus

 RLi

bra

Venu

s/Sa

turn

 27

Dec

embe

rM

orni

ngSa

gitt

ariu

sTa

urus

 R O

pp 0

3Li

bra

Plan

et p

osit

ions

201

3

Mon

thVe

nus

Mar

sJu

pite

rS

atur

nCo

njun

ctio

ns

Janu

ary

Mor

ning

Cap

rico

rnus

Taur

us R

Libr

aFe

brua

ryM

orni

ngC

apri

corn

usTa

urus

 RLi

bra

Mar

chSu

p C

onj 2

8 A

quar

ius

Taur

usLi

bra

RA

pril

Even

ing

Con

j Sun

 18

Taur

usLi

bra 

R O

pp 2

8Ve

nus/

Mar

s 06

May

Even

ing

Ari

esTa

urus

Libr

a R

Venu

s/Ju

pite

r 28

June

Even

ing

Ari

esC

onj S

un 1

9Li

bra

RJu

lyEv

enin

gTa

urus

Taur

usLi

bra

RM

ars/

Jupi

ter 

22A

ugus

tEv

enin

gG

emin

iG

emin

iLi

bra

Sept

embe

rEv

enin

gC

ance

rG

emin

iLi

bra

Venu

s/Sa

turn

 20

Oct

ober

Even

ing

Can

cer

Gem

ini

Libr

aN

ovem

ber

Max

. Elo

ng E

ast 0

1 Le

oG

emin

iC

onj S

un 0

6D

ecem

ber

Even

ing

Leo

Gem

ini R

Libr

a

S_Sky_Guide_TEXT_3ed_04.indd 93 7/5/08 11:33:59 AM

 94

Plan

et p

osit

ions

201

4

Mon

thVe

nus

Mar

sJu

pite

rS

atur

nCo

njun

ctio

ns

Janu

ary

Inf 

Con

j 11

Vir

goG

emin

i R O

pp 5

Libr

aFe

brua

ryM

orni

ngV

irgo

Gem

ini R

Libr

aM

arch

Max

. Elo

ng W

est 2

2 V

irgo

 RG

emin

i RLi

bra

RA

pril

Mor

ning

Vir

go R

 Opp

 08

Gem

ini

Libr

a R

May

Mor

ning

Vir

go R

Gem

ini

Libr

a R

 Opp

 10

June

Mor

ning

Vir

go R

Gem

ini

Libr

a R

July

Mor

ning

Vir

goC

onj S

un 2

4Li

bra

RA

ugus

tM

orni

ngV

irgo

Can

cer

Libr

a R

Venu

s/Ju

pite

r 18

Mar

s/Sa

turn

 27

Sept

embe

rM

orni

ngLi

bra

Can

cer

Libr

aO

ctob

erSu

p C

onj 2

5Sc

orpi

usC

ance

rLi

bra

Nov

embe

rEv

enin

gSa

gitt

ariu

sC

ance

rC

onj S

un 1

8Ve

nus/

Satu

rn 1

3D

ecem

ber

Even

ing

Sagi

ttar

ius

Can

cer

Libr

a

Plan

et p

osit

ions

201

5

Mon

thVe

nus

Mar

sJu

pite

rS

atur

nCo

njun

ctio

ns

Janu

ary

Even

ing

Cap

rico

rnus

Can

cer

RLi

bra

Febr

uary

Even

ing

Aqu

ariu

sC

ance

r R

 Opp

 6Sc

orpi

usVe

nus/

Mar

s 21

Mar

chEv

enin

gPi

sces

Can

cer

RSc

orpi

usA

pril

Even

ing

Pisc

esC

ance

r R

Scor

pius

RM

ayEv

enin

gTa

urus

Can

cer

Scor

pius

 R O

pp 2

3Ju

neM

ax. E

long

 Eas

t 06

Con

j Sun

 14

Can

cer

Scor

pius

RJu

lyEv

enin

gG

emin

iC

ance

rSc

orpi

us R

Venu

s/Ju

pite

r 01

, 31

Aug

ust

Inf 

Con

j 15

Gem

ini

Con

j Sun

 26

Scor

pius

RVe

nus/

Mar

s 29

Sept

embe

rM

orni

ngC

ance

rLe

oSc

orpi

usO

ctob

erM

ax. E

long

 Wes

t 26

Leo

Leo

Scor

pius

Mar

s/Ju

pite

r 17

Venu

s/Ju

pite

r 26

Nov

embe

rM

orni

ngLe

oLe

oC

onj S

un 3

0Ve

nus/

Mar

s 03

Dec

embe

rM

orni

ngV

irgo

Leo

Scor

pius

S_Sky_Guide_TEXT_3ed_04.indd 94 7/5/08 11:33:59 AM

 95

Plan

et p

osit

ions

201

6

Mon

thVe

nus

Mar

sJu

pite

rS

atur

nCo

njun

ctio

ns

Janu

ary

Mor

ning

Vir

goLe

oSc

orpi

usVe

nus/

Satu

rn 0

9Fe

brua

ryM

orni

ngLi

bra

Leo

RSc

orpi

usM

arch

Mor

ning

Libr

aLe

o R

Scor

pius

Apr

ilM

orni

ngSc

orpi

us R

Leo 

R O

pp 0

8Sc

orpi

us R

May

Mor

ning

Scor

pius

 R O

pp 2

2Le

o R

Scor

pius

RJu

neSu

p C

onj 0

6Li

bra

RLe

oSc

orpi

us R

 Opp

 03

July

Even

ing

Libr

aLe

oSc

orpi

us R

Aug

ust

Even

ing

Libr

aLe

oSc

orpi

us R

Mar

s/Sa

turn

 25

Venu

s/Ju

pite

r 27

Sept

embe

rEv

enin

gSc

orpi

usC

onj S

un 2

6Sc

orpi

us R

Oct

ober

Even

ing

Scor

pius

Vir

goSc

orpi

usVe

nus/

Satu

rn 3

0N

ovem

ber

Even

ing

Sagi

ttar

ius

Vir

goSc

orpi

usD

ecem

ber

Even

ing

Cap

rico

rnus

Vir

goC

onj S

un 1

0

Plan

et p

osit

ions

201

7

Mon

thVe

nus

Mar

sJu

pite

rS

atur

nCo

njun

ctio

ns

Janu

ary

Max

. Elo

ng E

ast 1

2A

quar

ius

Vir

goSc

orpi

usFe

brua

ryEv

enin

gA

quar

ius

Vir

goSc

orpi

usM

arch

Inf 

Con

j 25

Pisc

esV

irgo

 RSc

orpi

usA

pril

Mor

ning

Ari

esV

irgo

 R O

pp 0

7Sc

orpi

us R

May

Mor

ning

Taur

usV

irgo

 RSc

orpi

us R

June

Max

. Elo

ng W

est 0

3Ta

urus

Vir

go R

Scor

pius

 R O

pp 1

5Ju

lyM

orni

ngC

onj S

un 2

7V

irgo

Scor

pius

RA

ugus

tM

orni

ngG

emin

iV

irgo

Scor

pius

RSe

ptem

ber

Mor

ning

Gem

ini

Vir

goSc

orpi

us R

Oct

ober

Mor

ning

Leo

Con

j Sun

 26

Scor

pius

Venu

s/M

ars 

05N

ovem

ber

Mor

ning

Vir

goLi

bra

Scor

pius

Venu

s/Ju

pite

r 13

Dec

embe

rM

orni

ngV

irgo

Libr

a C

onj S

un 2

1Ve

nus/

Satu

rn 2

5

Not

es: R

 = r

etro

grad

ing,

 Opp

 = o

ppos

itio

n, S

up C

onj =

 sup

erio

r co

njun

ctio

n, I

nf C

onj =

 infe

rior

 con

junc

tion

, Con

j Sun

 = c

onju

ncti

on w

ith 

the 

Sun,

 Max

. Elo

ng =

 max

imum

 el

onga

tion

S_Sky_Guide_TEXT_3ed_04.indd 95 7/5/08 11:34:00 AM

 96

S_Sky_Guide_TEXT_3ed_04.indd 96 7/5/08 11:34:00 AM

Index

Absolute magnitude 7Achernar (Alpha Eridani) 48Acrux 52Adhara (Epsilon Canis Majoris)

60Alcyone (in Pleiades) 74Aldebaran (Alpha Tauri) 74Algieba (Gamma Leonis) 78Algol (Beta Persei) 8, 74Alnasl (Gamma Sagittarii) 68Alnath (Beta Tauri) 74Alphard (Alpha Hydrae) 62Alpheratz (Alpha Andomedae)

72, 86Altair (Alpha Aquilae) 68, 84Andromeda Galaxy (M31) 72Andromeda the Chained Maiden

72, 86Antares (Alpha Scorpii) 6, 66Antlia the Air Pump 62Apex of the Sun’s Motion 82Apparent magnitude 6Apus the Bird of Paradise 52Aquarius the Water­Carrier 70Aquila the Eagle 68, 84Ara the Altar 52Arcturus (Alpha Bootis) 80Argo Navis the Ship Argo 50Aries the Ram 72Asterisms 1Astronomical twilight 12Auriga the Charioteer 74Beehive, The (Praesepe, M44) 18, 

76Bellatrix (Gamma Orionis) 58Beta Ceti 56Beta Lyrae 84Betelgeuse (Alpha Orionis) 9, 58Binoculars 89Bootes the Herdsman 80Caelum the Engraving Tool 48California Nebula (N1499) 74Cancer the Crab 76Canes Venatici the Hunting Dogs 

80Canis Major the Great Dog 60Canis Minor the Small Dog 60Canopus (Alpha Carinae) 50Capella (Alpha Aurigae) 74Capricornus the Sea­Goat 70Carina the Ship’s Keel 50Castor (Alpha Geminorum) 76Celestial equator 9Celestial poles 9Celestial sphere 9Centaurus A 52Centaurus the Centaur 52Cepheid variables 8Cetus the Sea Monster 56Circinus the Compasses 52Clouds of Magellan 48Coal Sack, the 18, 52

Columba the Dove 58Coma Berenices (Berenice’s Hair) 

80Coma Cluster (Melotte 111) 80Comets 17Conjunction of planet 16Constellations 1Constellations, table of brightest

2–3Corona Borealis the Northern 

Crown 82Corvus the Crow 64Crab Nebula (M1) 74Crater the Cup 62Crossing the meridian 9Crux the (Southern) Cross 52Cygnus the Swan 84Dark nebulae 18Declination 12Delphinus the Dolphin 84Delta Aquarids meteor shower 70Deneb (Alpha Cygni) 84Denebola (Beta Leonis) 78Distances in sky 8Dorado the Swordfish 4830 Doradus 48Double stars 8Draco the Dragon 82Dunlop 18 (Iota Pictoris) 48Dunlop 227 54Eclipses of Moon 14Eclipses of Sun 14Ecliptic 12Emission nebulae 18Enif (Epsilon Pegasi) 86Epsilon Lyrae 84Equuleus the Colt 86Eridanus the River 48, 58Eta Aquarids meteor shower 70Eta Carinae 50Evening star 16False Cross 50First Point of Aries 72Flamsteed numbers 6Flare stars 9Fomalhaut (Alpha Piscis Austrini) 

70Fornax the Furnace 56Galactic equator 68Galaxies  N55 56  N205 (M110) 72  N221 (M32) 72  N224 (M31, Andromeda 

Galaxy) 72  N253 56  N598 (M33) 72  N3623 (M65) 78  N3627 (M66) 78  N4472 (M49) 64, 80  N4486 (M87) 64  N4594 (M104) 64  N5128 (Centaurus A) 52  N5236 (M83) 64  N6744 54Galaxies 18, 18–19, 80Gamma Aquilae 84Gamma Canceri 76

Gamma Velorum 50Gemini the Twins 76Geminids meteor shower 76Giant stars 7Globular clusters 18  47 Tucanae 48  M3 (N5272) 80  M4 (N6121) 66  M13 (N6205) 82  M15 86  M22 (N6656) 68  N6752 54  NGC 362 48  Omega Centauri (N5139) 52Great Square of Pegasus, the 72,

86Grus the Crane 54, 70Hadar (Beta Centauri) 52Hamal (Alpha Arietes) 72Helical rising 60Helix Nebula 70Hercules 82Herschel 3670 48Herschel 4330 50Herschel 4332 50Hipparchos 66Horologium the Clock 48Hyades 74Hydra the Female Water Snake 60,

62, 64Hydrus the Male Water Snake 48I2391 (Omicron Velorum) 50I2602 50I4665 82Indus the Indian 54Inferior conjunction 16Iota Pictoris (Dunlop 18) 48Irregular variable stars 9Jewel Box, the 18, 52Jupiter 16Kappa Crucis 52Kaus Australis (Epsilon

Sagittaurii) 68Lacerta the Lizard 86Large Magellanic Cloud 48Leo the Lion 78Leo Minor the Small Lion 78Leonids meteor shower 78Lepus the Hare 58Libra the Scales 66Light grasp 89Light year 6Lupus the Wolf 52Lyra the Harp 84M1 (Crab Nebula) 74M3 (N5272) 80M4 (NGC 6121) 66M6 (Butterfly Cluster) 66M7 (NGC 6475) 66M8 (Lagoon Nebula) 68M11 (Wild Duck Nebula) 68M13 (NGC 6205) 82M15 86M16 (NGC 6611) 68M17 (Swan Nebula) 68M18 (N6613) 68M20 (Trifid Nebula) 68M21 (NGC 6531) 68

M22 (NGC 6656) 68M24 68M25 (I4725) 68M27 (Dumbbell Nebula) 84M31 (Andromeda Galaxy) 72M32 (NGC 221) 72M33 (NGC 598) 72M35 (NGC 2168) 76M41 (NGC 2287) 60M42 (Orion Nebula) 58M43 (NGC 1982) 58M44 (Praesepe) 76M45 (Pleiades) 74M46 (NGC 2437) 60M47 (NGC 2423) 60M48 (NGC 2548) 60M49 (NGC 4472) 64M57 (Ring Nebula) 84M65 (NGC 3623) 78M66 (NGC 3627) 78M67 (NGC 2682) 76M83 (NGC 5236) 64M87 (NGC 4486) 64M104 (‘Sombrero Hat’ galaxy) 

64M110 (NGC 205) 72Magellanic Clouds 48Magnitude of stars 6Manger, the (Praesepe) 76Maria 14Markab (Alpha Pegasi) 86Mars 16Melotte 20 74Melotte 111 (Coma Cluster) 80Menkar (Alpha Ceti) 56Mensa the Table Mountain 48Mercury 16Messier catalogue 19Meteor showers 17  Arietids 72  Delta Aquarids 70  Eta Aquarids 70  Geminids 76  Leonids 78  Orionids 58  Quadrantids 80  table of brightest 17  Taurids 74Microscopium the Microscope 54Milky Way, the 18Mimosa (Beta Crucis) 52Minor planets 17Mira (Omicron Ceti) 56Mirzam (Beta Canis Majoris) 60Monoceros the Unicorn 60Moon, main features of 14Morning star 16Multiple stars 8  Acrux 52 Adhara (Epsilon Canis Majoris)

60  Algeiba (Gamma Leonis) 78  Alpha Centauri 52  Beta Lyrae 84  Castor 76  Delta Orionis 58  Dunlop 227 54  Gamma Andromedae 72

 97

S_Sky_Guide_TEXT_3ed_04.indd 97 7/5/08 11:34:00 AM

98

  Gamma Velorum 50  Herschel 3670 48  Herschel 4330 50  Herschel 4332 50  Iota Orionis 58  Iota Pictoris (Dunlop 18) 48  k Puppis 60  Mu Crucis 52  Struve 1120 60  Struve 1121 60  Theta Eridani 56Musca the Fly 52N4472 (M49) 80N5272 (M3) 80naked­eye doubles  Alpha Librae 66  Epsilon Lyrae 84  Sigma Tauri 74  Theta Tauri 74Nebulae 18–19  California Nebula (N1499) 74  Coal Sack (dark) 52  Crab Nebula (M1) 74  Eta Carinae Nebula (N3372) 

50  Keyhole Nebula (N3372) 50  Lagoon Nebula (M8) 68  Lambda Crucis 52  M43 (N1982) 58 North America Nebula

(N7000) 84  Orion Nebula (N1976) 58  Rosette Nebula (N2237) 60  Swan Nebula (M17) 68  Tarantula Nebula (N2070) 48  Trifid Nebula (M20) 68  Veil Nebula (N6960) 84  Wild Duck Nebula (M11) 68New General Catalogue 19NGC 55 56NGC 104 (47 Tucanae) 48NGC 253 56NGC 362 48NGC 1360 56NGC 1499 (California Nebula) 

74NGC 1952 (M1) 74NGC 1976 (Orion Nebula) 58NGC 1980 58NGC 1981 58NGC 1982 (M43) 58NGC 2070 (Tarantula Nebula) 48NGC 2168 (M35) 76NGC 2237 (Rosette Nebula) 60NGC 2287 60NGC 2354 60NGC 2362 60NGC 2423 60NGC 2437 60NGC 2451 60NGC 2548 60NGC 2682 (M67) 76NGC 3242 62NGC 3372 (Eta Carinae Nebula) 

50NGC 3766 50NGC 4472 64NGC 4486 64

NGC 4594 64NGC 4755 (Jewel Box Cluster) 

52NGC 5128 (Centaurus A) 52NGC 5139 (Omega Centauri) 52  NGC 6205 (M13) 82NGC 6231 66NGC 6705 (M11) 68NGC 6720 (Ring Nebula) 84NGC 6744 54NGC 6752 54NGC 6853 (Dumbbell Nebula) 

84NGC 6960 (Veil Nebula) 84NGC 7000 (North America 

Nebula) 84NGC 7293 (Helix Nebula) 70Norma the Set Square 52North Galactic Pole 80Northern Cross 84Novae 9, 66Occultation 16Octans the Octant 54Omega Centauri 18, 52Omicron Velorum 50Open clusters 17–18  Butterfly Cluster (M6) 66  Collinder 399 84  Coma Cluster (Melotte 111) 

80  Hyades 74  I4665 66, 82  Jewel Box (N4755) 52  M7 (N6475) 66  M8 (N6613) 68  M16 (N6611) 68  M21 (N6531) 68  M24 (‘star cloud’) 68  M25 (I4725) 68  M35 (N2168) 76  M41 (N2287) 60  M46 (N2437) 60  M47 (N2423) 60  M48 (N2548) 60  M67 (N2682) 76  Melotte 20 (Alpha Persei) 74  N752 72  N1980 58  N1981 58  N2362 60  N2451 60  N3766 50  N6231 66  Omicron Velorum (I2391) 50  Pleiades (M45) 74  Praesepe (M44) 76  Theta Carinae (I2602) 50  Trapezium (Theta Orionis) 58  Trumpler 24 66Ophiuchus the Serpent­Holder 

66, 82Opposition, planet at 15Orion Nebula (M42, NGC 1976) 

58Orion the Hunter 58Pavo the Peacock 54Pegasus the Flying Horse 86Perseus 74, 86

Phases of Moon 13Phoenis the Phoenix 48Pictor the Painter’s Easel 48Pisces the Fish 72Piscis Austrinus the Southern Fish 

70Planetary movements, table of

91–95Planetary nebulae 18  Dumbbell Nebula 84  Helix Nebula (N7293) 70  N1360 56  N3132 62  N3242 62  Ring Nebula 84Planets, identifying 16Planets, movements of inner 16Planets, movements of outer

14–16Pleiades 18, 74Pointers, the 52Polaris 54Pollux (Beta Geminorum) 76Praesepe (Beehive Cluster, M44) 

76Precession of the Equinoxes 13,

66, 72Procyon (Alpha Canis Minoris)

60Proxima Centauri 8, 52Puppis the Ship’s Poop 60Pyxis the Ship’s Compass 60Quarantids meteor shower 80Rasalgethi (Alpha Herculi) 82Rasalhague (Alpha Ophiuchi) 82Reflection nebulae 18Regulus (Alpha Leonis) 78Resolution 89Reticulum the Reticle 48Retrograding of planet 14–15Rigel (Beta Orionis) 58Right ascension 12Rigil Kent (Alpha Centauri) 52Rosette Nebula 60Royal Stars of Persia 70, 74, 78Sagitta the Arrow 84Sagittarius the Archer 68Satellites 17Saturn 16Saucepan, the 58Scheat (Beta Pegasi) 86Scorpius the Scorpion 66Sculptor the Sculptor’s Chisel 56Scutum the Shield 68Serpens Caput the Serpent’s Head 

66Serpens Cauda the Serpent’s Tail 

66, 68Sextans the Sextant 62Shaula (Gamma Scorpii) 66Sidereal time 21Sigma Octantis 54Sirius (Alpha Canis Majoris) 60Small Magellanic Cloud 48Soothis (Sirius) 60South celestial pole 9South Galactic Pole 56Spica (Alpha Virginis) 64

Stars 1Stars, table of brightest 7Struve 1120 60Struve 1121 60Summer Solstice 76Supergiant stars 7Superior conjunction 16Supernovas 18Taurids meteor shower 74Taurus the Bull 74Teapot, the (in Sagittarius) 68Telescopes 89Telescopium the Telescope 54Terminator 14Theta Carinae 50Theta Eridani 56Theta Orionis 58Trapezium, the 58Triangulum 72Triangulum Australe 52Trifid Nebula 18, 68Tropic of Cancer 76Tropic of Capricorn 70Trumpler 24 66Tucana the Toucan 48, 5447 Tucanae 18, 48Ursa Major the Great Bear 78, 80Variable stars 8  Mira­type    Mira 56    R Car 50    R Hor 48    R Leo 78    R Lep 58    S Car 50    U Ori 58 Eclipsing    Algol 74    Beta Lyrae 84  Semi­regular L2 Puppis 50Vega (Alpha Lyrae) 84Vela the Ship’s Sail 50Venus 16Vernal equinox 12, 72Virgo Cluster 64, 80Virgo the Young Maiden 64Vulpecula the Fox 84White dwarf stars 8Wild Duck Nebula (M11) 68Winter Triangle, the 84Zodiac 13

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