Cygnus Constellation

8/2/2019 Cygnus Constellation

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TODAYSCONSTELLATION4/11/2011

CYGNUS (Swan)

By Ashish Mishra

2nd Year

Physical sciences


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CONTENTS

i. Introduction.

ii. Main stars

iii. Asterism

iv. Mythologyv. Deep sky objects


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E


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INTRDUCTION

Cygnus : a northern constellation , is situated inthe Milky Way.

Bordering Constellations : Cepheus, Draco,Lyra, Vulpecula, Pegasus & Lacerta.

Right Ascension : 21h 45m 44.5s

Declination : +40

Visible at latitudes between +90 and 40.

Best visible at 21:00 hrs during the month ofSeptember.


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INTRDUCTION


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MAIN STARS

1) alpha Cygni or Deneb ("the tail")

2) beta Cygni or Albireo marks the head of theswan.


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MAIN STARS

3) gamma Cygni or Sadr ("chest") - a yellow-white supergiant.

is surrounded by a diffuse nebula, IC I318, alsoknown as the Gamma Cygni region.


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MAIN STARS

4 ) delta Cygni : magnitude = 3

components :

a blue-white supergiant a yellow-white companion star

a magnitude 12 orange star.

5) epsilon Cygni is an orange giant


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ASTERISM

Northern Cross

The stars are: Deneb (Alpha Cyg), Albireo (BetaCyg), Sadr (Gamma Cyg), Delta Cyg, and Gienah(Epsilon Cyg).


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ASTERISM

Summer triangle

Deneb, Vega (in the constellation of Lyra), andAltair (in the constellation of Aquila) mark theSummer Triangle.


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MYTHOLOGY Greek : Zeus and the goddess Nemesis.

In order to escape from Zeus, Nemesis changedherself into many different animals. When she changedinto a goose, Zeus immediately transformed himself into awonderful swan and won the love of Nemesis.

The goddess became pregnant, delivered an egg and then

abandoned it. Fortunately, a shepherd found the egg andgave it to Leda, the wife of Tyndareus, the king ofSparta. From that egg came Helen of Troy. Helen was sobeautiful that Leda claimed her as her own child.

The constellation Cygnus was formed to celebrate thelovely swan.


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MYTHOLOGYGreek :two close friends : Cygnus and Phaeton, who werecontinually competing. One day, they each each challenged theother to a race across the sky, around the Sun, and back to

Earth. In an effort to gain the advantage, they both cut tooclosely to the Sun and their chariots were burned up. They bothfell to the Earth and were knocked unconscious. Uponrecovering, Cygnus began looking for his friend, Phaeton, anddiscovered his body trapped by the roots of a tree at thebottom of the Eridanus River.In an effort to retrieve hisfriends body and give it a proper burial, Cygnus repeatedly dove

into the river, but could not reach his friends body. While hesat grieving on the bank of the river, Cygnus begged for Zeus tohelp him. Zeus replied that if he gave Cygnus the body of aswan, he would be able to dive deeply enough to retrieve hisfriends body. However, if Cygnus did take on the body of aswan, he would also be giving up his immortality and would onlylive as long as a swan would normally live. Cygnus readily agreed

to this in order to retrieve his friends body and give him aproper burial, allowing his friends spirit to travel into theafterlife. In honor of this great unselfish act, Zeus placedCygnus image (that of a swan) into the night sky.


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DEEPSKYOBJECTSNorth America Nebula

An emission nebulaclose to Deneb


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DEEPSKYOBJECTSVeil Nebula :an ancient supernova remnant

cloud of heated and ionized gas and dust to thesouth of Epsilon Cygni

covers approximately 3 degrees of the sky.


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DEEPSKYOBJECTS Crescent Nebula:an emission nebula

located between Gamma and Eta Cygni formed by the fast stellar wind from the Wolf-

Rayet star WR 136 (HD 192163)


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DEEPSKYOBJECTS

Cygnus X-1 :X-ray source close to the starEta Cygni

caused by a black hole accreting matter in abinary star system.

Cyg A :Radio galaxy

Meteor Showers: October Cygnids :Between September 26th

and October 10th

Kappa Cygnids :from July 26th to September

1st. The maximum of the shower activity seemsto occur on August 18th with an average rate of6 meteors per hour.


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DEEPSKYOBJECTS

The Fireworks Galaxy(Discovered by William

Herschel) :site of more supernova sightingsthan any other galaxy.

an intermediate spiral galaxy lying on the borderbetween the constellations Cygnus and Cepheus,

approximately 10 million light-years away fromEarth.


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DEEPSKYOBJECTS Blinking Nebula: Size 25


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DEEPSKYOBJECTS Dumbbell Nebula :actually located in Vulpecula

& the first planetary nebula ever discovered.


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DEEPSKYOBJECTS

The Cygnus Rift or the Northern Coalsack

The Great Rift (Dark Rift or Dark River) :aseries of overlapping, non-luminous, moleculardust clouds that are located between theSolarSystem and the Sagittarius Arm of the MilkyWay Galaxyat a distance of about100 parsecsfrom Earth. The clouds are estimated to containabout 1 million solar masses of plasma and dust.

To thenaked eye, the Great Rift appears as adark lane that divides the bright band of theMilky Way lengthwise, through about one-thirdof its extent, and is flanked by lanes ofnumerous stars.


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DEEPSKYOBJECTS

The Cygnus Rift or the Northern Coalsack

Starting at the constellation Cygnus, where it isknown as the Cygnus Rift or Northern Coalsack,the Great Rift stretches toAquila; toOphiuchus, where it broadens out; toSagittarius, where it obscures the GalacticCenter; and finally toCentaurus.

One of the most important regions it obscuresis theCygnus OB2 association, a large cluster ofyoung stars and one of the largest regions of

star formation near the Earth.


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DEEPSKYOBJECTS

The Milky Way near Cygnus showing the darklane of the Great Rift.


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Thank you

Documents

Cygnus Constellation