Oct 2015 Volume 22 Number 04 Page 1

Star Gazer News

Newsletter of the Delmarva Stargazers www.delmarvastargazers.org

Upcoming Events: Meeting Oct 6

th 7PM Smyrna Church

No Frills Star Party Oct 8th to 10

th 4 day/3night Trap Pond

Meeting Nov 3rd

7PM Smyrna Church

From the Prez… No Frills Star Party. When: Oct. 8th thru 10th 2015. Where: Trap Pond State

Park, Laurel Delaware. The registration fee includes the following: Camping fee for the observing area (campers are permitted to park by their telescopes) — Star Gazer Cof-fee continuously —- Soup or chili on Thurs-day and Friday nights — Fish fry on Satur-day afternoon —- Soda and hot dogs will be available at minimal cost. Next month, we will be gathering at Trap Pond for our No Frills Star Party. This will be our second time here for the star party. The first one was small, but did give us a chance to work through some of the logistics of the new location- if you were there and have any feedback maybe you could write an editorial article about it... It was also a great time for door prizes, our prize to attendee ratio was at an all time high and chances of winning were very good. Things are starting to fall into place now, more information will be coming out on the web page and Facebook. So October 8th or so plan on packing up your toys and coming down to Trap Pond. Last month I went down to Trap Pond

on Saturday for the night, the weather was

OK, not great, but we did get to do some

observing. This was for our monthly observ-

ing session. I had a chance to look through

this big Mead with a 3D Binocular viewer,

if you were at the spring party, you may

have seen one and heard the presentation on

it. Needless to say, the views were impres-

sive, I felt like I could have fallen into

M13. People seem to be finding out about

what we are doing here and are showing up,

the owners of this came down from PA for

about four or five nights.

The September Meeting: Some of us came early and met at Sheridan's Irish Pub for dinner, a little pricier than Smyrna Diner, but a nice change of scenery. Not sure what October will bring but we will let you all know ahead of time. I asked Pj to share his thoughts at the meeting concerning the club newsletter. He seems to think the newsletter is dead and just does not know it yet. I want to challenge all of us to prove him wrong. I think the newsletter is an important part of the club. Before I ever came to a meeting, I read several is-sues, got a feel for what you all were about. If not for reading those issues, I may never have showed up. I would like to take a moment to thank Pj for his work on the newsletter, he has done a great job keeping in going out during a drought of member submitted articles. No need to point fingers or play the blame game, but I think most of us would agree that a few articles off of the inter-net do not a newsletter not make. We are

Oct 2015 Volume 22 Number 04 Page 2

the ones that will make it work, or not. If you have never written an article, now would be the time. We recently cut back to every other month, but if we start sending stuff in, it will go back to monthly. So write something: an article, an editorial, an observing report, or send in a pic. Do not worry about how good of a writer you are, that is not what it is about, and big problems can be fixed. Spell check and grammar check will find a lot of problems and what it misses, you will find when you read the newsletter, I know I al-ways find something. When I was asked to do this, I thought writing would be the worse part and was told the same thing, but I have enjoyed it, so far. So, write something about your trip to Cherry Springs, your new telescope, how metal detecting relates to astronomy or why quantum entanglement is a myth…

Thank you to Don Surles who took some time to share with us about the New Horizon mission to Pluto and his meeting Clyde Tom-baugh, who discovered Pluto in 1930. For more on the mission this is a good starting place: http://www.nasa.gov/mission_pages/newhorizons/main/index.html At the meeting Francis Ingram shared a presentation on The Ashen Light, that is reflected light from the dark side of Ve-nus, thank you Francis. Very interesting, I especially enjoyed the time taken to discus paradigms and how they can affect our ob-servations and conclusions, and how they are constantly changing. Earlier that day my wife and I were discussing the same thing, how we tend to judge history through the lens of our society or paradigm. If you missed it, there is always next month, the meeting will be on October 6 at 7:00pm. Hope to see many of you there.

Your 2015-2016 Officers Office Officer Phone email President Peter Graham President-elect Doug Towner Secretary Michael Lecuyer Treasurer Kathy Sheldon 302-422-4695 memomsheldon@comcast.net Past President Lyle Jones 302-382-3764 worm1647@comcast.net

Urgent...Urgent...Urgent!!! Delmarva Star Gazers is approaching its 23rd anniversary. I have been a Star Gazer since almost a year before the offi-cial Day 1 in 1993. And I have enjoyed every one of those days. Ours is a wonder-ful organization where we share, we teach, we learn and we enjoy the camaraderie of fellow Gazers. Tonight I learned that we are having difficulty in getting sufficient Star Gazer info from fellow Star Gazers for our news-letter. Frustration was evident. A “club” newsletter without news from club members is not a true club newsletter...it is sim-ply a regurgitation of data taken from the internet and other sources. For that reason I am challenging each member to volunteer a simple half page ar-ticle for our newsletter. The topic is your choice...but the necessity for your contri-bution is absolutely real. A good starting point would be a quick bio of yourself and why astronomy is important to you. Please consider this...if we cannot fill some of the pages of our newsletter with info from club members then our 22+ year newsletter will go the way of

the dodo bird and simply cease to exist. I sincerely do not want that to occur. The original Star Gazers are growing old...some have passed and the younger originals are approaching 70 years old. John Kennedy talked of the passing of a torch....”that the torch has been passed to a new generation of Americans”. The

torch of leadership and responsibility for

the various duties to ensure Delmarva Star

Gazers continues to prosper and fill the

need for local amateur astronomers is being

passed. Will you be there to accept the

torch? Don Surles...

Oct 2015 Volume 22 Number 04 Page 3

Measure the moon's size and

distance during

the next lunar eclipse

By Ethan Siegel The moon represents perhaps the first great paradox of the night sky in all of human history. While its angular size is easy to measure with the unaided eye from any location on Earth, ranging from 29.38 arc-minutes (0.4897°) to 33.53 arc-minutes (0.5588°) as it orbits our world in an el-lipse, that doesn't tell us its physical size. From its angular size alone, the moon could just as easily be close and small as it could be distant and enormous. But we know a few other things, even relying only on naked-eye observations. We know its phases are caused by its geometric configuration with the sun and Earth. We know that the sun must be farther away (and hence, larger) than the moon from the phe-nomenon of solar eclipses, where the moon passes in front of the sun, blocking its disk as seen from Earth. And we know it un-dergoes lunar eclipses, where the sun's light is blocked from the moon by Earth. Lunar eclipses provided the first evidence that Earth was round; the shape of the portion of the shadow that falls on the moon during its partial phase is an arc of

a circle. In fact, once we measured the ra-dius of Earth (first accomplished in the 3rd century B.C.E.), now known to be 6,371 km, all it takes is one assumption—that the physical size of Earth's shadow as it falls on the moon is approximately the physical size of Earth—and we can use lunar eclipses to measure both the size of and the dis-tance to the moon! Simply by knowing Earth's physical size and measuring the ratios of the angu-lar size of its shadow and the angular size of the moon, we can determine the moon's physical size relative to Earth. During a lunar eclipse, Earth's shadow is about 3.5 times larger than the moon, with some slight variations dependent on the moon's point in its orbit. Simply divide Earth's radius by your measurement to figure out the moon's radius! Even with this primitive method, it's straightforward to get a measurement for the moon's radius that's accurate to within 15% of the actual value: 1,738 km. Now that you've determined its physical size and its angular size, geometry alone enables you to determine how far away it is from Earth. A lunar eclipse is coming up on September 28th, and this supermoon eclipse will last for hours. Use the partial phases to meas-ure the size of and distance to the moon, and see how close you can get!

Image credit: Daniel Munizaga (NOAO South/CTIO EPO), using the Cerro Tololo Inter-American Observatory, of an eight-image se-

quence of the partial phase of a total lunar eclipse.

Oct 2015 Volume 22 Number 04 Page 4

How Don became an astronomer I was born a long time ago in North Carolina. I grew up on a tobacco, cotton, corn and soybean farm. Our work necessi-tated a lot of night work...and our skies were not polluted with electric light. Our lights were kerosene lanterns and lamps. Many nights of handling dry tobacco or gathering the days’ picked cotton of-fered a canopy of stars that would be the envy of any current star gazer. All I could do was look up and imagine what was up there. My family did not have a telescope or even a binocular...but I remember think-ing the sky was like black velvet with dia-monds sprinkled on it. The last semester of college (spring 1969) I needed another elective 4 hour course to meet graduation requirements in addition to those hours required for my ma-jor. I chose astronomy. During that course I had access to a telescope of my own...after I assembled it. I had access to cameras, film, darkroom...and other folks interested in astronomy...and dark skies. I remember well my Ring Nebula picture...it reminded me of a black and white fried egg picture. That astronomy course cultivated those memories of the dark nights in the cotton and tobacco fields. Fast forward to 1985....16 years of several jobs in several states, 6 houses, 5 moves, 2 children...and the 1st heart at-tack at age 38. I decided to re-prioritize my priorities....Family first, myself sec-ond, job third would be my MO for the fu-ture. Shortly after recovering from that scare I decided I wanted a tele-scope...along with a new car, new appli-ances, new van. My MO was to alleviate the uncertainty and anxiety of older cars and appliances. My reasoning...at the 1985 price of $10,000 per day of hospital car-diac care the price of new appliances and autos along with the absence of stress seemed to be a bargain. I still believe in that scenario. Less STRESS! Shortly after taking delivery of that first scope, a 10” Coulter Odyssey, I began attending star parties. I learned about ca-maraderie, learn-teach-learn, and the many changes and challenges of amateur astron-omy. It wasn’t very long until the seeds of a local astronomy club were planted in my mind...and in a couple of years Delmarva Star Gazers was SUCCESSFULLY formed. The rest is history. So many Star Gazers, so many star parties, so many telescopes, mir-ror making, computers, cameras, so many nights under the stars...so many great

memories! Oh...I am now retired from 35 years in DuPont Engineering. Today I enjoy gar-dening, photography, wood turning, making wood toys, metal detecting, and of course amateur astronomy. See you at the Super moon Lunar

Eclipse September 27-28, 2015. Please consider submitting your own bio for our newsletter.

Don Surles

Oct 2015 Volume 22 Number 04 Page 5

are pleased to announce the

No Frills Star Party. When: Oct. 8th thru 10th 2015.

Where: Trap Pond State Park, Laurel Delaware. The registration fee includes the following:

Camping fee for the observing area (campers are permitted to park by their telescopes) — Star Gazer Coffee continuously —- Soup or chili on Thursday and Friday nights — Fish fry

on Saturday afternoon —- Soda and hot dogs will be available at minimal cost. For more info check the website for updates.

Grus From Wikipedia

Grus is a constellation in the southern sky. Its name is Latin for the crane, a type of bird. It is one of twelve constellations conceived by Petrus Plancius from the observa-tions of Pieter Dirkszoon Keyser and Frederick de Houtman. Grus first appeared on a 35-cm (14 in) diameter celestial globe published in 1598 in Amsterdam by Plancius and Jodocus Hondius and was depicted in Johann Bayer's star atlas Uranometria of 1603. French explorer and as-tronomer Nicolas Louis de Lacaille gave Bayer designations to its stars in 1756, some of which had been previously considered part of the neighbouring constellation Piscis Austri-nus. The constellations Grus, Pavo, Phoenix and Tucana are collectively known as the "Southern Birds". The constellation's brightest star, Al-pha Gruis, is also known as Alnair and appears as a 1.7-magnitude blue-white star. Beta Gruis is a red giant variable star with a minimum magnitude of 2.3 and a maximum magnitude of 2.0. Six star systems have been found to have planets: the red dwarf Gliese 832 is one of the closest stars to Earth to have a planetary system. Another—WASP-95—has a planet that or-bits every two days. Deep-sky objects found in Grus include the planetary nebula IC 5148, also known as the Spare Tyre Nebula, and a group of four interacting galaxies known as the Grus Quartet. History The stars that form Grus were origi-nally considered part of the neighbouring con-stellation Piscis Austrinus (the southern fish), with Gamma Gruis seen as part of the fish's tail. The stars were first defined as a separate constellation by the Dutch astronomer Petrus Plancius, who created twelve new con-stellations based on the observations of the southern sky by the Dutch explorers Pieter

Dirkszoon Keyser and Frederick de Houtman, who had sailed on the first Dutch trading expedi-tion, known as the Eerste Schipvaart, to the East Indies. Grus first appeared on a 35-cm diameter celestial globe published in 1598 in Amsterdam by Plancius with Jodocus Hondius. Its first depiction in a celestial at-las was in the German cartographer Johann Bayer's Uranometria of 1603. De Houtman in-cluded it in his southern star catalogue the same year under the Dutch name Den Reygher, "The Heron", but Bayer followed Plancius and Hondius in using Grus. An alternative name for the constella-tion, Phoenicopterus (Latin "flamingo"), was used briefly during the early 17th century, seen in the 1605 work Cosmographiae Generalis by Paul Merula of Leiden University and a c. 1625 globe by Dutch globe maker Pieter van den Keere. Astronomer Ian Ridpath has reported the symbolism likely came from Plancius origi-nally, who had worked with both of these peo-ple. Grus and the nearby constellations Phoe-nix, Tucana and Pavo are collectively called the "Southern Birds". The stars that correspond to Grus were generally too far south to be seen from China. In Chinese astronomy, Gamma and Lambda Gruis may have been included in the tub-shaped as-terism Bàijiù, along with stars from Piscis Austrinus. In Central Australia, the Arrernte and Luritja people living on a mission in Her-mannsburg viewed the sky as divided between them, east of the Milky Way representing Ar-rernte camps and west denoting Luritja camps. Alpha and Beta Gruis, along with Fomalhaut, Alpha Pavonis and the stars of Musca, were all claimed by the Arrernte. Characteristics Grus is bordered by Piscis Austrinus to the north, Sculptor to the northeast, Phoenix to the east, Tucana to the south, Indus to the southwest, and Microscopium to the west. Bayer straightened the tail of Piscis Austrinus to

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make way for Grus in his Uranometria. Covering 366 square degrees, it ranks 45th of the 88 modern constellations in size and covers 0.887% of the night sky. The three-letter ab-breviation for the constellation, as adopted by the International Astronomical Union in 1922, is "Gru". The official constellation boundaries, as set by Eugène Delporte in 1930, are defined as a polygon of 6 segments. In the equatorial coordinate system, the right ascen-sion coordinates of these borders lie between 21h 27.4m and 23h 27.1m, while the declination coordinates are between −36.31° and −56.39°. Grus is located too far south to be seen by observers in the British Isles and the northern United States, though it can easily be seen from Florida or California; the whole constellation is visible to observers south of latitude 33°N. Notable features Stars Keyser and de Houtman assigned twelve stars to the constellation. Bayer depicted Grus on his chart, but did not assign its stars Bayer designations. French explorer and astronomer Nicolas Louis de Lacaille labelled them Alpha to Phi in 1756 with some omissions. In 1879, American astronomer Benjamin Gould added Kappa, Nu, Omicron and Xi, which had all been catalogued by Lacaille but not given Bayer designations. Lacaille considered them too faint, while Gould thought otherwise. Xi Gruis had originally been placed in Micro-scopium. Conversely, Gould dropped Lacaille's Sigma as he thought it was too dim. Grus has several bright stars. Marking the left wing is Alpha Gruis, a blue-white star of spectral type B6V and apparent magni-tude 1.7, around 101 light-years from Earth. Its traditional name, Alnair, means "the bright one" and refers to its status as the brightest star in Grus. Alnair is around 380 times as luminous and has over 3 times the di-ameter of the Sun. Lying 5 degrees west of Al-nair, denoting the Crane's heart is Beta Gruis, a red giant of spectral type M5III. It has a diameter of 0.8 astronomical units (AU) (if placed in the Solar System it would extend to the orbit of Venus) located around 170 light-years from Earth. It is a variable star with a minimum magnitude of 2.3 and a maximum magnitude of 2.0. An imaginary line drawn from the Great Square of Pegasus through Fomalhaut will lead to Alnair and Beta Gruis. Lying in the northwest corner of the constellation and marking the crane's eye is Gamma Gruis, a blue-white subgiant of spectral type B8III and magnitude 3.0 lying around 211 light-years from Earth. Also known as Al Dhanab, it has finished fusing its core hydro-gen and has begun cooling and expanding, which will see it transform into a red giant. There are several naked-eye double

stars in Grus. Forming a triangle with Alnair and Beta, Delta Gruis is an optical double whose components—Delta1 and Delta2—are sepa-rated by 45 arcseconds. Delta1 is a yellow gi-ant of spectral type G7III and magnitude 4.0, 309 light-years from Earth, and may have its own magnitude 12 orange dwarf companion. Del-ta2 is a red giant of spectral type M4.5III and semiregular variable that ranges between magnitudes 3.99 and 4.2, located 325 light-years from Earth. It has around 3 times the mass and 135 times the diameter of our sun. Mu Gruis, composed of Mu1 and Mu2, is also an op-tical double—both stars are yellow giants of spectral type G8III around 2.5 times as mas-sive as the Sun with surface temperatures of around 4900 K. Mu1 is the brighter of the two at magnitude 4.8 located around 275 light-years from Earth, while Mu2 the dimmer at mag-nitude 5.11 lies 265 light-years distant from Earth. Pi Gruis, an optical double with a variable component, is composed of Pi1 Gruis and Pi2. Pi1 is a semi-regular red giant of spectral type S5, ranging from magnitude 5.31 to 7.01 over a period of 191 days, and is around 532 light-years from Earth. One of the brightest S-class stars to Earth viewers, it has a companion star of apparent magnitude 10.9 with sunlike properties, being a yellow main sequence star of spectral type G0V. The pair make up a likely binary system. Pi2 is a giant star of spectral type F3III-IV located around 130 light-years from Earth, and is of-ten brighter than its companion at magnitude 5.6. Marking the right wing is Theta Gruis, yet another double star, lying 5 degrees east of Delta1 and Delta2. RZ Gruis is a binary system of apparent magnitude 12.3 with occasional dimming to 13.4, whose components—a white dwarf and main sequence star—are thought to orbit each other roughly every 8.5 to 10 hours. It belongs to the UX Ursae Majoris subgroup of cataclysmic variable star systems, where material from the donor star is drawn to the white dwarf where it forms an accretion disc that remains bright and outshines the two component stars. The system is poorly understood, though the donor star has been calculated to be of spectral type F5V. These stars have spectra very simi-lar to novae that have returned to quiescence after outbursts, yet they have not been ob-served to have erupted themselves. The Ameri-can Association of Variable Star Observers recommends watching them for future events. CE Gruis (also known as Grus V-1) is a faint (magnitude 18–21) star system also composed of a white dwarf and donor star; in this case the two are so close they are tidally locked. Known as polars, material from the donor star does not form an accretion disc around the white dwarf, but rather streams directly onto

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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. Contact a club officer for more information.

it. Six star systems are thought to have planetary systems. Tau1 Gruis is a yellow star of magnitude 6.0 located around 106 light-years away. It may be a main sequence star or be just beginning to depart from the sequence as it expands and cools. In 2002 the star was found to have a planetary companion. HD 215456, HD 213240 and WASP-95 are yellow sunlike stars discovered to have two planets, a planet and a remote red dwarf, and a hot Jupiter respectively; this last—WASP-95b—completes an orbit round its sun in a mere two days. Gliese 832 is a red dwarf of spectral type M1.5V and apparent magnitude 8.66 located only 16.1 light-years distant; hence it is one of the nearest stars to the Solar System. A Jupiter-like planet—Gliese 832 b—orbiting the red dwarf over a period of 9.4±0.4 years was discovered in 2008. WISE 2220−3628 is a brown dwarf of spectral type Y, and hence one of the coolest star-like objects known. It has been calculated as being around 26 light-years dis-tant from Earth. Deep-sky objects IC 5148, the spare-tyre nebula as im-aged by the ESO Faint Object Spectrograph and Camera (EFOSC2) on the New Technology Tele-scope at La Silla Nicknamed the spare-tyre nebula, IC 5148 is a planetary nebula located around 1 degree west of Lambda Gruis. Around 3000 light-years distant, it is expanding at 50 kilometres a second, one of the fastest rates of expansion of all planetary nebulae. Northeast of Theta Gruis are four in-teracting galaxies known as the Grus Quartet. These galaxies are NGC 7552, NGC 7590, NGC 7599, and NGC 7582. The latter three galaxies occupy an area of sky only 10 arcminutes across and are sometimes referred to as the "Grus Triplet," although all four are part of a larger loose group of galaxies called the IC 1459 Grus Group. NGC 7552 and 7582 are exhib-iting high starburst activity; this is thought to have arisen because of the tidal forces from interacting. Located on the border of Grus with Piscis Austrinus, IC 1459 is a pecu-liar E3 giant elliptical galaxy. It has a fast counterrotating stellar core, and shells and ripples in its outer region. The galaxy has an apparent magnitude of 11.9 and is around 80 Mly distant.

NGC 7424 is a barred spiral galaxy with an apparent magnitude of 10.4. located around 4 degrees west of the Grus Triplet. Approxi-mately 37.5 Mly distant, it is about 100,000 Lys in diameter, has well defined spiral arms and is thought to resemble the Milky Way. Two ultraluminous X-ray sources and one supernova have been observed in NGC 7424. SN 2001ig was discovered in 2001 and classified as a Type IIb supernova, one that initially showed a weak hydrogen line in its spectrum, but this emission later became undetectable and was re-placed by lines of oxygen, magnesium and cal-cium, as well as other features that resembled the spectrum of a Type Ib supernova. A massive star of spectral type F, A or B is thought to be the surviving binary companion to SN 2001ig, which was believed to have been a Wolf–Rayet star. Located near Alnair is NGC 7213, a face-on type 1 Seyfert galaxy located approxi-mately 71.7 Mly from Earth. It has an apparent magnitude of 12.1. Appearing undisturbed in visible light, it shows signs of having under-gone a collision or merger when viewed at longer wavelengths, with disturbed patterns of ionized hydrogen including a filament of gas around 64,000 light-years long. It is part of a group of ten galaxies. NGC 7410 is a spiral galaxy discovered by British astronomer John Herschel during ob-servations at the Cape of Good Hope in October 1834. The galaxy has a visual magnitude of 11.7 and is approximately 122 Mly distant from Earth. Chinese Astronomy The modern constellation Grus lies across one of the quadrants symbolized by the

The Black Tortoise of the North (北方玄武, Běi Fāng Xuán Wǔ), and The Southern Asterisms (近南極星區, Jìnnánjíxīngōu), that divide the sky

in traditional Chinese uranography. Constellation Grus in Chinese sky is not fully seen. Al Na'ir (Alpha Gruis) and Gruid (Beta Gruis) are bright stars in this constellation that possibly never seen in Chi-nese sky. The name of the western constellation

in modern Chinese is 天鶴座 (tiān hè zuò), mean-ing "the heaven crane constellation".

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