May 2015 Volume 21 Number 11 Page 1

Star Gazer News

Newsletter of the Delmarva Stargazers www.delmarvastargazers.org

Upcoming Events: Meeting ! May 5

th 7 PM Smyrna Church

Star Party ! May 14-18 Dusk Trap Pond SP

President’s Comments…

Well by the time you read this, you should know whether or not the club has had an observing session at Trap Pond State Park. As of Monday April 13 the weather does not look promising for the weekend of April 17 and 18. Based upon Mi-chael Lecuyer’s recommended Sky Cover Map from National Weather Service, the cloud cover only worsens over Saturday and Saturday night. We wanted to observe this coming weekend and then during the day on Saturday work out the logis-tics for our May Stargaze. The Park will be building or has built a new entrance for Cypress Field. Consequently, we needed to determine in-gress and egress from the observing field. Since I did not reserve the pavilions quickly enough, we do not have access to the pavilions for the Stargaze. Therefore, we need to determine where to set up our large tent. Delaware Cooperative Electric has all the paperwork needed to install the transmission line to the Field and we need to stake out the location of the outlet boxes. We just need some time on the observing field to develop a plan! The moon is not conducive to viewing over the weekend of April 23 and 24 due to its illumination and time of rising. I will try to set up a meeting over the next two weeks at Trap Pond to work out the logistics for our May star party. Join us for that meeting if you like.

I do have one request for our members! We have need of 6 to 10 portable tables to be used in the large tent at the Stargaze. As stated previ-ously, we don’t have access to the pavilions for this star party but will have them available for No-Frills in the Fall. I don’t want to purchase

any for perhaps a onetime use. Please email me, if you have one to lend and be sure that if you

lend us a table you have your name on it. We do have door prizes arriving in the mail and have some meteorites-- thanks to Dave Holden of Sky Stones. We will be making scope-coats out of white Tyvek for your telescopes and at a very reasonable price! This will probably happen on Saturday May 16Th. I purchased my scope- coat over 15 years ago when the club first made them; it has not torn and has kept my scopes rain and dust free. It was a good buy! If you have not registered for our Stargaze, please take some time and to do that. It will be a fun event with lots to do and see. And hope-fully with good weather!! My recently con-structed 10” truss tube telescope has seen first

light, so my new telescope can’t be blamed for any bad weather--- if we have any!

Proof of first light through an eyepiece--- The

Moon! I plan to use this scope during the Stargaze and if I finish my 4” Delmarva Schiefspiegler by then I will have that there also. The head that holds both the main mirror tube and secondary mirror tube has been especially challenging with the 12.2 degree cross cut and a 52 degree bevel. I have only re-made it five times and, I might add, produced a lot of good kindling wood for my fireplace.

A picture of one of my attempts at making the Schiefspiegler head that holds the main mirror tube

and secondary mirror tube.

The agenda for the May 5 meeting is as follows: Club administration

• Membership list

• Newsletter

• Our Don Surles Mirror Making Workshop may

(Continued on page 2)

May 2015 Volume 21 Number 11 Page 2

have a new home.

• April 17 and 18 @ Trap Pond (a bust!). I

will try to schedule one for June 2016.

• Outreaches---

Don Surles—Oxford, VA

Elkton Central Library –April 21@

6:30

North East Rt. 40 Stony Run Apts –

April 23@ 6:30

Discuss and set-up the Stargaze Star Party (May 14-May 17).

• Check-in -- Michael Lecuyer and Leonard White

• Port- a- Potties-- Lyle Jones

• Water Transport—

• Tent set-up ------

• Doorprizes and raffle?

• Buying for star party --- Doug Towner & Lyle Jones

• Soups- Spaghetti and ?

• Cooks (Thursday and Friday night)

• Trash—

• Trailer - Keith Lohmeyer

• Fish Fry – Volunteers

• Clean-up Constellation/Objects of Month --- Jerry Truitt will used the World Wide Telescope Programs

• Astronomical apps which you can put on

your Smart devices—Lyle and Peter Graham

See you at our next meeting on May 5 or at the Stargaze May 14th through 17th!

Delmarva Stargazers 2015 Membership List

A.J. Baker Dan Boulet Alan Bundschuh Dennis Dellies Raymond & Patricia Deidrichs Marlon DeTorres Frank Filemeyer Peter Graham Dave Groski Ralph Gruen John Guerra Chuck Harrison

Deane Horowitz John Hutzell Lyle Jones Michael Lecuyer Greg Lee Keith Lohmeyer Sean Lutz-Swank Dawn Miller Joe Morris Joe Muehlethaler Nathan J. Naddeo Tony Pasta Larry Pieper

Thomas Planchon Thomas Pomponio David D. Pletsch Gary Porter Pj Riley Henry E Jr. Rozanski Kathy Sheldon Tomasz G. Smolinksi Keith Snyder Doug Towner Jerry Truitt Billie Westergard

May 2015 Volume 21 Number 11 Page 3

Your 2014-2015 Officers Office Officer Phone email President Lyle Jones 302-382-3764 worm1647@comcast.net President-elect Peter Graham Secretary Treasurer Kathy Sheldon 302-422-4695 memomsheldon@comcast.net Past President Don Surles 302-653-9445 don.surles@verizon.net

For Sale 25’ Spirit of America Coachman Travel Trailer

Neighbor is selling a 2005 Spirit 25 Foot Travel trailer. Used a total of seven times by past and present owners. It is very good shape and has been winterized. Travel trailer will sleep 6 people and has a full bathroom. Asking $5700. Call Sara Herbert @302-674-3670.

The Delmarva Stargazers are selling our 10" Meade LX 200 telescope outfit which includes super wedge, tripod, dewshield, battery, inverters and controllers. The drive system has recently been repaired and upgrade. Asking $ 1900 or best offer!

The Delmarva Stargazers

are pleased to announce

Star Gaze XXI Star Party We'll be celebrating 21 years of Stargazing on Delmarva.

Thursday, May 14, 2015

through Sunday, April 17, 2015

Trap Pond State Park,

Laurel DE

Bring a friend, family, and maybe your optics and join the fun

Check http://www.delmarvastargazers.org/archive/SG2015/index.html

For Registration!

May 2015 Volume 21 Number 11 Page 4

Centaurus From Wikipedia, the free encyclopedia Visible at latitudes between +25° and −90°. Best visible at 21:00 (9 p.m.) dur-ing the month of May.

Centaurus is a bright constellation in the southern sky. One of the largest constellations, Centaurus was included among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it re-mains one of the 88 modern constellations. In Greek mythology, Centaurus represents a centaur; a creature that is half human, half horse (another constellation named af-ter a centaur is one from the zodiac: Sag-ittarius). Notable stars include Alpha Cen-tauri, the nearest star system to our own Solar System, its neighbour in the sky Beta Centauri, and V766 Centauri, one of the largest stars yet discovered. The constel-lation also contains Omega Centauri, the brightest globular cluster as visible from Earth and one of the largest known.

Stars Centaurus contains several very bright stars because of its position in the Milky Way; in addition, its alpha and beta stars are used to find the constellation Crux. The constellation has 281 stars above magnitude 6.5, meaning that they are visi-ble to the unaided eye, the most of any constellation. Alpha Centauri, the closest star to the Sun, has a high proper motion; it will be a mere half-degree from Beta Centauri in approximately 4000 years.

Alpha Centauri is a triple star sys-tem that contains Proxima Centauri, the nearest star to the Sun. Traditionally

called Rigil Kentaurus or Toliman, meaning "foot of the centaur", the system has an overall magnitude of -0.28 and is 4.4 light-years from Earth. The primary and secondary are both yellow-hued stars; the primary, is of magnitude -0.01 and the sec-

ondary is of magnitude 1.35. Proxima, the tertiary star, is a red dwarf of magnitude 11.0; it is almost 2 degrees away from the primary and secondary and has a period of approximately one million years. Also a flare star, Proxima has minutes-long out-bursts where it brightens by over a magni-tude. The primary and secondary have a pe-riod of 80 years and will be closest to each other as seen from Earth in 2037 and 2038. In addition to Alpha Centauri (the 3rd brightest star in the sky), a second

first magnitude star, Beta Centauri, is part of Centaurus. Also called Hadar and Agena, Beta Centauri is a double star; the

primary is a blue-hued giant star of magni-tude 0.6, 525 light-years from Earth. The secondary is of magnitude 4.0 and has a very small separation. A bright binary star

in Centaurus is Gamma Centauri, which ap-pears to the naked eye at magnitude 2.2. The primary and secondary are both blue-white hued stars of magnitude 2.9; their period is 85 years. Centaurus also has many dimmer double stars and binary stars. 3 Centauri is a double star with a blue-white hued primary of magnitude 4.6 and a secondary of magni-tude 6.1. The primary is 298 light-years from Earth. Centaurus is home to many variable

stars. R Centauri is a Mira variable star with a minimum magnitude of 11.8 and a maximum magnitude of 5.3; it is 2100 light-years from Earth and has a period of 18

months. V810 Centauri is a semiregular variable.

BPM 37093 is a white dwarf star whose carbon atoms are thought to have formed a crystalline structure. Since diamond also consists of carbon arranged in a crystal-line lattice (though of a different con-figuration), scientists have nicknamed this

star "Lucy" after the Beatles song "Lucy in the Sky with Diamonds." Deep-sky objects

ω Centauri (NGC 5139), despite being listed as the constellation's "omega" star, is in fact a naked-eye globular cluster, located at a distance of 17,000 light-years with a diameter of 150 light-years. It is the largest and brightest globular cluster in the Milky Way, at ten times the size of the next-largest cluster, it has a magni-tude of 3.7. It is also the most luminous globular cluster in the Milky Way, at over

one million solar luminosities. Omega Cen-tauri is classified as a Shapley class VIII cluster, which means that its center is loosely concentrated. It is also the only globular cluster to be designated with a

Bayer letter; the globular cluster 47 Tuca-nae is the only one designated with a Flam-steed number. It contains several million stars, most of which are yellow dwarf stars, but also possesses red giants and blue-white stars; the stars have an average age of 12 billion years. This has prompted suspicion that Omega Centauri was the core of a dwarf galaxy that had been absorbed by the Milky Way. Omega Centauri was deter-mined to be nonstellar in 1677 by the Eng-lish astronomer Edmond Halley, though it was visible as a star to the ancients. Its status as a globular cluster was determined by James Dunlop in 1827. To the unaided

May 2015 Volume 21 Number 11 Page 5

eye, Omega Centauri appears fuzzy and is obviously non-circular; it is approximately half a degree in diameter, the same size as the full Moon. Centaurus is also home to open clus-ters. NGC 3766 is an open cluster 6300 light-years from Earth that is visible to the unaided eye. It contains approximately 100 stars, the brightest of which are 7th magnitude. NGC 5460 is another naked-eye open cluster, 2500 light-years from Earth, that has an overall magnitude of 6 and con-tains approximately 40 stars. There is one bright planetary nebula in Centaurus, NGC 3918, also known as the Blue Planetary. It has an overall magnitude of 8.0 and a central star of magnitude 11.0; it is 2600 light-years from Earth. The Blue Planetary was discovered by John Herschel and named for its color's similar-ity to Uranus, though the nebula is three times larger than the planet. Centaurus is rich in galaxies as well. NGC 4622 is a face-on spiral galaxy located 200 million light-years from Earth (redshift 0.0146). Its spiral arms wind in both directions, which makes it nearly im-possible for astronomers to determine the rotation of the galaxy. Astronomers theo-rize that a collision with a smaller com-panion galaxy near the core of the main galaxy could have led to the unusual spiral structure. NGC 5253, a peculiar irregular galaxy, is located near the border with Hy-dra and M83, with which it likely had a close gravitational interaction 1-2 billion years ago. This may have sparked the gal-axy's high rate of star formation, which continues today and contributes to its high surface brightness. NGC 5253 includes a large nebula and at least 12 large star clusters. In the eyepiece, it is a small galaxy of magnitude 10 with dimensions of 5 arcminutes by 2 arcminutes and a bright nu-cleus. NGC 4945 is a spiral galaxy seen edge-on from Earth, 13 million light-years away. It is visible with any amateur tele-scope, as well as binoculars under good conditions; it has been described as "shaped like a candle flame", being long and thin (16' by 3'). In the eyepiece of a large telescope, its southeastern dust lane becomes visible. Another galaxy is NGC 5102, found by star-hopping from Iota Cen-tauri. In the eyepiece, it appears as an elliptical object 9 arcminutes by 2.5 arcminutes tilted on a southwest-northeast axis. One of the closest active galaxies to

Earth is the Centaurus A galaxy, NGC 5128, at a distance of 11 million light-years

(redshift 0.00183). It has a supermassive black hole at its core, which expels mas-sive jets of matter that emit radio waves due to synchrotron radiation. Astronomers posit that its dust lanes, not common in elliptical galaxies, are due to a previous merger with another galaxy, probably a spi-ral galaxy. NGC 5128 appears in the optical spectrum as a fairly large elliptical gal-axy with a prominent dust lane. Its overall magnitude is 7.0, and it has been seen un-der perfect conditions with the naked eye, making it one of the most distant objects visible to the unaided observer. In equato-rial and southern latitudes, it is easily found by star hopping from Omega Centauri. In small telescopes, the dust lane is not visible; it begins to appear with about 4 inches of aperture under good conditions. In large amateur instruments, above about 12 inches in aperture, the dust lane's west-northwest to east-southeast direction is easily discerned. Another dim dust lane on the east side of the 12 arcminute by 15

arcminute galaxy is also visible. ESO 270-17, also called the Fourcade-Figueroa Ob-ject, is a low-surface brightness object believed to be the remnants of a galaxy; it does not have a core and is very difficult to observe with an amateur telescope. It measures 7 arcminutes by 1 arcminute. It likely originated as a spiral galaxy and underwent a catastrophic gravitational in-teraction with Centaurus A around 500 mil-lion years ago, stopping its rotation and destroying its structure.

NGC 4650A is a polar-ring galaxy lo-cated at a distance of 136 million light years from Earth (redshift 0.01). It has a central core made of older stars that re-sembles an elliptical galaxy, and an outer ring of young stars that orbits around the core. The plane of the outer ring is dis-torted, which suggests that NGC 4650A is the result of a galaxy collision about a billion years ago. This galaxy has also been cited in studies of dark matter, be-cause the stars in the outer ring orbit too quickly for their collective mass. This suggests that the galaxy is surrounded by a dark matter halo, which provides the neces-sary mass. One of the closest galaxy clusters to Earth is the Centaurus Cluster, located at a distance of 160 million light-years (redshift 0.0114). It has a cooler, denser central region of gas and a hotter, more diffuse outer region. The intracluster me-dium in the Centaurus Cluster has a high concentration of metals (elements heavier than helium) due to a large number of su-

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pernovae. This cluster also possesses a plume of gas whose origin is unknown.

History

While Centaurus now has a high south-ern latitude, at the dawn of civilization it was an equatorial constellation. Preces-sion has been slowly shifting it southward for millennia, and it is now close to its maximal southern declination. Thousands of years from now Centaurus will, once again, be at lower latitudes and be visible world-wide. The figure of Centaurus can be traced back to a Babylonian constellation known as the Bison-man (MUL.GUD.ALIM). This being was depicted in two major forms: firstly, as a 4-legged bison with a human head, and secondly, as a being with a man's head and torso attached to the rear legs and tail of a bull or bison. It has been closely asso-ciated with the Sun god Utu-Shamash from very early times. The Greeks depicted the constellation as a centaur and gave it its current name. It was mentioned by Eudoxus in the 4th cen-tury BCE and Aratus in the 3rd century BCE. In the 2nd century AD, Claudius Ptolemy catalogued 37 stars in Centaurus. Large as it is now, in earlier times it was even larger, as the constellation Lupus was treated as an asterism within Centaurus, portrayed in illustrations as an unspeci-fied animal either in the centaur's grasp or impaled on its spear. The Southern Cross, which is now regarded as a separate constellation, was treated by the ancients as a mere asterism formed of the stars com-posing the centaur's legs. Additionally, what is now the minor constellation Cir-cinus was treated as undefined stars under the centaur's front hooves. According to the Roman poet Ovid (Fasti v.379), the constellation honors the centaur Chiron, who was tutor to many of the earlier Greek heroes including Heracles (Hercules), Theseus, and Jason, the leader of the Argonauts. However, most authorities consider Sagittarius to be the civilized Chiron, while Centaurus represents a more uncouth member of the species. The legend associated with Chiron says that he was ac-cidentally poisoned with an arrow shot by Hercules, and was subsequently placed in the heavens. Other History In Chinese astronomy, the stars of Centaurus are found in three areas: the Az-

ure Dragon of the East (東方青龍, Dōng Fāng Qīng Lóng), the Vermillion Bird of the

South (南方朱雀, Nán Fāng Zhū Què), and the

Southern Asterisms (近南極星區, Jìnnánjíxīn-gōu). Not all of the stars of Centaurus can be seen from China, and the unseen stars were classified among the Southern Aster-isms by Xu Guangqi, based on his study of western star charts. However, most of the brightest stars of Centaurus, including α Cen, θ Cen, ε Cen and η Cen, can be seen in the Chinese sky. Some Polynesian peoples considered the stars of Centaurus to be a constella-tion as well. On Pukapuka, Centaurus had two names: Na Mata-o-te-tokolua and Na Lua-mata-o-Wua-ma-Velo. In Tonga, the constel-lation was called by four different names: O-nga-tangata, Tautanga-ufi, Mamangi-Halahu, and Mau-kuo-mau. Alpha and Beta Centauri were not named specifically by the people of Pukapuka or Tonga, but they were named by the people of Hawaii and the Tuamotus. In Hawaii, the name for Alpha Centauri was either Melemele or Ka Maile-hope and the name for Beta Centauri was ei-ther Polapola or Ka Maile-mua. In the Tuamotu islands, Alpha was called Na Kuhi and Beta was called Tere.

Namesakes

Two United States navy ships, USS Centaurus (AKA-17) and USS Centaurus (AK-264), are named after the constellation. The Centaurus is a Mega Mall and com-mercial/residential complex in Islamabad, Pakistan. Construction started in 2005 and the three 41-storey towers, the tallest structures in Islamabad, were completed by late 2012. The shopping mall was officially opened on February 17, 2013. The Centaurus originally included a 7 star hotel, con-struction of which is yet to begin.

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May 2015 Volume 21 Number 11 Page 8

Astrophotos by members and friends

How to Join the Delmarva Stargazers: Anyone with an interest in any aspect of astronomy is welcome NAME_______________________________________________________________New_______Renew___________ ADDRESS_____________________________________________________________________________________ CITY, STATE & ZIP______________________________________________________________________________ E-MAIL ADDRESS (If any)_________________________________________________________________________ Do you need the newsletter snail mailed to you (Y/N)?___________________________________________________ Please attach a check for $15 made payable to Delmarva Stargazers and mail to Kathy Sheldon, 20985 Fleatown Rd, Lincoln, DE 19960. Call club President Lyle Jones at 302-382-3764 for more information.

The Tadpoles of IC 410

This an image I made this winter while in AZ using my AP 130mm refractor and is my first attempt at narrowband imaging and was combined in the classical Hubble pallet. From APOD, " This telescopic close-up shows off the otherwise faint emission nebula IC 410 in striking false-colors. It also features two remarkable inhabitants of the cos-mic pond of gas and dust below and right of center, the tadpoles of IC 410. The picture is a composite of images taken through narrow band filters. The narrow band image data traces atoms in the nebula, with emission from sulfur atoms in red, hydrogen atoms in green, and oxygen in blue. Partly obscured by foreground dust, the nebula itself sur-rounds NGC 1893, a young galactic cluster of stars that energizes the glowing gas. Com-posed of denser cooler gas and dust the tadpoles are around 10 light-years long, potentially sites of ongoing star formation. Sculpted by wind and radiation from the cluster stars, their tails trail away from the cluster's central region. IC 410 lies some 12,000 light-years away, toward the constellation Auriga." - Joe Morris