The Prairie AstronomerFebruary 2016 Volume 57, Issue #2

MSRAL

The Newsletter of the Prairie Astronomy Club

Gravitational WavesObserved

FebruaryProgram:

ObservingPrograms

Jim Kvasnicka

Image Credit: SXS

The Prairie Astronomer

NEXT PAC MEETING: February 23, 7:30pmat Hyde ObservatoryPROGRAMObserving Programs, by Jim Kvasnicka.

Jim will present an overview of the Astronomical League’sobserving programs. It will benefit any new members whoare thinking of starting an observing program. It will coverhow to get started, which program to start with. He will alsoreview the observing awards earned by PAC members.

CONTENTS

4 Meeting Minutes

5 Double Stars

7 Close Encounters

9 TX68

10 Galaxies & Asteroids

13 Tethys

14 LIGO

17 March Observing

18 Puppis

19 Closest New Stars

10 From the Archives

21 Club Information

Buy the book! The PrairieAstronomy Club: Fifty Yearsof Amateur Astronomy.Order online from Amazon orlulu.com.

FUTURE PROGRAMS

March: Space Law Part I - Mark EllisApril: Space Law Part II - Elsbeth Magilton & Prof Frans Von der DunkJune: Solar Star PartyAugust: NSP Review

The Prairie Astronomer 3

PAC E-MAIL:info@prairieastronomyclub.org

PAC-LIST:Subscribe through GoogleGroups.To post messages to the list, sendto the address:pac-list@googlegroups.com

The Prairie Astronomerc/o The Prairie Astronomy Club, Inc.P.O. Box 5585Lincoln, NE 68505-0585

ADDRESS

EVENTS

Photo by Brian Sivill

2016 STAR PARTY DATES

WEBSITESwww.prairieastronomyclub.orghttps://nightsky.jpl.nasa.govwww.hydeobservatory.infowww.nebraskastarparty.orgwww.OmahaAstro.comPanhandleastronomyclub.comwww.universetoday.com/www.planetary.org/home/http://www.darksky.org/

PAC Meeting

PAC MeetingTuesday February 23rd, 2016, 7:30pmHyde Observatory

PAC MeetingTuesday March 29th, 2016, 7:30pmHyde Observatory

Astronomy Day, Sunday, April 17 at Morrill Hall

PAC MeetingTuesday April 26th, 2016, 7:30pmHyde Observatory

Newsletter submission deadline March 19

Star PartyDate

Star PartyDate

Lunar PartyDate

January Jan 1st Jan 8thFebruary Jan 29th Feb 5thMarch Mar 4th Mar 11thApril Apr 1st Apr 8th Apr 15thMay Apr 29th May 6th May 13thJune May 27th Jun 3rdJuly Jul 1st Jul 8th

NSP July 31st- Aug 5th

August Jul 29th Aug 5th Aug 12thAugust Aug 26th Sep 2nd Sep 9thSeptember Sep 23rd Sep 30thOctober Oct 21st Oct 28thNovember Nov 25th Dec 2ndDecember Dec 23rd Dec 30th

The Prairie Astronomer 4

Minutes for the meeting ofTuesday January 26, 2016

President Jim Kvasnicka calledthe meeting to order. Welcomemembers and guests.

Jim reviewed upcoming eventsand activities.

The next PAC meeting will beTuesday February 23, at Hyde.The next PAC star parties will beJan 29,and February 5 at theBusboom farm.

Jim also reviewed benefits andopportunities for members.

Jim provided his monthlyobserving report.

Club business:

Zack Thompson mentioned thatMorrill Hall will have its SundayWith A Scientist on April 17,which will be the annualAstronomy Day. Zack askedmembers who would like tovolunteer for this event to

contact him by March 1st tocoordinate this event.

The club audit will occurSaturday February 6, 2016.The audit committee consistsof Secretary, Lee Taylor, MikeKearns and Rick Brown.

Adjourn to the program, Howto Use Your Telescope.

Respectfully submitted by

Lee Taylor

PAC Meeting Minutes

xkcd.com

The Prairie Astronomer 5

Positions, separations, and position angles for 2000

LEGEND: R.A. = Right Ascension (2000.0) Dec. = Declinationmag. = apparent visual magnitude sp. = spectral typeSep. = separation (in arc seconds) P.A. = position angle

Otto Struve (STT) 254, R.A. 0h 1.3m Dec. +60d 21.3'Primary: mag. 7.2~ (variable) Sp. C5p, Secondary mag. 8.3, sp. A Sep. 58" arc, P.A. 90 deg. (multiple opticaldouble) Colors seen in 10 inch: deep reddish-orange and bluish-white.(primary is Carbon star WZ Cas, other stars also nearby)

Sturve 3053, R.A. 0h 2.6m Dec. +66d 6.0'Primary: mag. 5.9, sp. G9III, Secondary mag. 7.3, sp. A1V Sep. 15.0" arc, P.A. 70 deg.Colors seen in 10 inch: Yellow and pale bluish.

Eta Cassiopeiae, R.A. 0h 49.10m Dec. +57d 49.0'Primary: mag. 3.4, sp. G0V, Secondary: mag. 7.5, sp. dM0 Sep. 12.8" arc, P.A. 317 deg. (period: 480 years)Colors seen in 10 inch: Off-white and faint reddish-orange.

ALMACH (Gamma And.), R.A. 2h 3.90m Dec. +42d 19.8'Primary: mag. 2.2 sp. K3III, Secondary: mag. 4.8 sp. B8V Sep. 9.8" arc, P.A. 64 deg. (mag. 6.3 companion ofGamma-B at 0.4" arc, p.a. 103 deg., closing separation).Colors seen in 10 inch: Yellow (Gold) and light blue.

6 Triangulae (Struve 227), R.A. 2h 12.37m Dec. +30d. 18.3'Primary: mag. 4.9, Sp. G5III, Secondary: mag. 6.5, Sp. F6V Sep. 3.9" arc, P.A. 69 deg.Colors seen in 9.25" SCT: Yellowish-white and bluish-white.

32 Eridani, R.A. 3h 54.29m Dec. -2d 57.3'Primary: mag. 4.5, sp. G8III, Secondary: mag. 6.1, sp. A2V Sep. 6.9" arc, P.A. 348 deg.Colors seen in 10 inch: Yellow and pale blue.

15 Geminorum, R.A. 6h 27.8m Dec. +20d 47.3'Primary: mag. 4.6, sp. K0, Secondary: mag. 8.5, sp. G0 Sep. 6.9" arc, P.A. 64 deg.Colors seen in 10 inch: Yellowish-orange and white.

Psi-5 Aurigae, R.A. 6h 46.75m Dec. +43d 34.6'Primary: Mag. 5.3 sp. G0V, Secondary: mag. 8.5 sp. M0V Sep. 31.1" arc, P.A. 38 deg.Colors seen in 10 inch: Off-white and faint orange.

38 Geminorum (STF 982), R.A. 6h 54.64m Dec. +13d 10.7'Primary: mag. 4.7, sp. A8/F0V, Secondary: mag. 7.7, sp. G6V Sep. 7.1" arc, P.A. 144 deg.Colors seen in 10 inch: White and faint orangish.

h3945 (ADS 5951, CMa), R.A. 7h 16.61m Dec. -23d 18.9'Primary: mag. 4.8 sp. K4III, Secondary: mag. 6.8, sp. A5 Sep. 26.6" arc, P.A. 55 deg.Colors seen in 10 inch: Orange and bluish-white."The Winter Albireo"

Common Double Stars with Significant Color Contrast

Dave Knisely

The Prairie Astronomer 6

S 548 (ADS 6087, Gem), R.A. 7h 27.7m Dec. +22d 8.0'Primary: mag. 6.9 sp. K5, Secondary mag. 8.9 sp. ?Sep. 35.5" arc, P.A. 277 deg.Colors: Orangish and bluish

Iota Cancri, R.A. 8h 46.70m Dec. +28d 45.6'Primary: mag. 4.0 sp. G8II, Secondary: mag. 6.6 sp. A3V Sep. 30.5" arc, P.A. 307 deg.Colors seen in 10 inch: Light yellow and pale blue.

Tau Leonis, R.A. 11h 27.94m Dec. +2d 51.3'Primary: mag. 4.9 sp. G8Iab, Secondary: mag. 7.4 sp. G5 Sep. 89.7' arc, P.A. 180 deg.Colors seen in 10 inch: Yellow and white.*nice low power pair with double 83 Leonis 20' at P.A. 298 deg.

2 Canum Venaticorum, R.A. 12h 16.13m Dec. +40d 39.6'Primary: mag. 5.7, sp. M1III, Secondary: mag. 8.7, sp. F7V Sep. 11.3" arc, P.A. 260 deg (2003).Colors seen in 10 inch: Yellowish-orange and pale bluish-white.

24 Comae Berenices, R.A. 12h 35.13m Dec. +18d 22.6'Primary: mag. 5.0 sp. K2III, Secondary: mag. 6.6 sp. A7V Sep. 20.3" arc, P.A. 271 deg.Colors seen in 10 inch: Yellow and pale blue.

Cor Caroli (Alpha CVn), R.A. 12h 56.00m Dec. +38d 19.1'Primary: mag. 2.9 sp. A0spe, Secondary: mag. 5.6, sp. F0V Sep. 18.8" arc, P.A. 230 deg.Colors seen in 10 inch: Bluish-white and off-white (cream).

Izar (Epsilon Bootis), R.A. 14h 44.99m Dec. +27d 4.5'Primary: mag. 2.4 sp. K0II, Secondary: mag. 5.1, sp. A2V Sep. 2.8" arc P.A. 339 deg.Colors seen in 10 inch: Yellow and light blue.

Xi Bootis, R.A. 14h 51.39m Dec. +19d 6.0'Primary: mag. 4.5, sp. G8V, Secondary: mag. 6.8, sp. K5V Sep. 6.8" arc P.A. 320 deg.Colors seen in 10 inch: Pale yellowish white and orange.

Antares (Alpha Sco). R.A. 16h 29.41m Dec. -26d 25.9'Primary: mag. 1.0v sp. M1I, Secondary: mag. 5.4 sp. B4 Sep. 2.6" arc P.A. 274 deg.Colors seen in 10 inch: Orange and light blue.

Ras Algethi (Alpha Her) R.A. 17h 14.65m Dec. +14d 23.4'Primary: mag. 3.2v sp. M5II Secondary: mag. 5.4, sp. F2/G3 Sep. 4.6" arc P.A. 104 deg.Colors seen in 10 inch: Reddish-orange and pale bluish-white.

95 Herculis. R.A. 18h 1.5m Dec. +21 deg. 36'Primary: mag. 4.9, Sp. A5III, Secondary: Mag. 5.2 sp. G5?Sep. 6.3" arc P.A. 256 deg.Colors seen in 10 inch: pale bluish-white and gold.

59 Serpentis, R.A. 18h 27.2m Dec. +0d 45.9'Primary: mag. 5.2, Sp. GOIII, Secondary: mag. 7.4, sp. ?Sep. 3.9" arc P.A. 320 deg.Colors seen in 10 inch: Yellowish-white and pale bluish-white

Omicron Draconis, R.A. 18h 51.20m Dec. +59d 23.3'Primary: mag. 4.6, Sp. G9III, Secondary: mag. 8.1, sp. K3III Sep. 36.5" arc P.A. 319 deg.Colors seen in 10 inch: Yellow and faint orangish

The Prairie Astronomer 7

SHJ 282 (O. Struve 525), Lyra), R.A. 18h 54.90m Dec. +33d 58.0'Primary: mag. 6.1, sp. G8III Secondary(s): mag. 9.1, sp. A8 B component Sep. 1.8" arc, P.A. 129 deg . (O. Str525) C component: mag. 7.7 Sp. A1, Sep. 45.4" arc P.A. 350 deg.Colors seen in 10 inch: Yellowish-white and bluish-white.

Albireo (Beta Cyg) 19h 30.72m Dec. +27d 57.6'Primary: mag. 3.1 sp. K3II Secondary: mag. 5.1 sp. B8V Sep. 34.3" arc P.A. 54 deg.Colors seen in 10 inch: Yellow and light blue.

ADS 12900 (Cyg). 19h 45.86m Dec. +35d 0.77'Primary: mag. 6.1 sp. K2? Secondary: mag. 8.6 sp. A2V Sep. 37.5" arc P.A. 25 deg.Colors seen in 10 inch: Yellow and blue.

Gamma Delphini, R.A. 20h 46.73m Dec. +16 deg. 7.8'Primary: mag. 4.4 sp. K1IV, Secondary: mag. 5.0 sp. F7V.Sep. 9.6" arc P.A. 268 deg.Colors seen in 10 inch: Yellowish and white (hint of blue)?

12 Aquari, R.A. 21h 4.1m Dec. -5 deg. 49'Primary: mag. 5.8 sp. G4III, Secondary: mag. 7.5 sp.?Sep. 2.5" arc P.A. 196 deg. (2003)Colors seen in 10 inch: Yellowish-white and pale bluish-white.

Delta Cephei R.A. 22h 29.20m Dec. +58d 25'Prmary: mag. 4.07 (variable) sp. F5-G3 Secondary: mag. 6.27 sp. B7 Sep. 40.8" arc P.A. 191 deg.Colors seen in 10 inch: Yellowish-white and light blue.

Editor’s note: for the benefit ofnewcomers to the club, I’m re-printing this story from the PAC50th Anniversary History Book(available in the club library or onlulu.com or Amazon). It’s one ofmy favorite PAC stories.——————————————One cool summer night in themid 60’s we were using the hilltop cow pasture of Earl Moser’sfather as our viewing site. It wasby far the darkest night I can re-call. I believe we were there forthe Perseid Meteor Shower. Ear-lier in the evening a cow had got-ten loose from the pen. Earlsimply shooed it away and backdown the hill. It was so dark I

didn’t see the cow but only heardit. By this time nearly everyonebut Pete Schultz and I had left. Iwas in a reclining lawn chairwrapped in a blanket countingmeteors. Pete was on the otherside of the hill crest taking wideangle images of the sky hopingto catch some great Meteors.He worked at the Miller andPaine Camera store at the timeand had ordered in some fantas-tic Linhof cameras and lenseswhich he then tested by shootingthe meteor shower with a medi-um format camera with fish eyelens.Earl went to drive back down tohis house for cocoa or something

like that. Hetried drivingout withouthis lights soas not tobother Pete’simaging normy darkadaption. But the night was sodark he managed to drive overhis camera and tripod. The tri-pod was toast but the tiresmissed the camera.While Earl was gone, with Peteconcentrating on his guidingand me counting meteors Isuddenly heard Pete breathinghard right behind my chair. Hedidn’t say anything. Just

Close Encounters of the Bovine KindRick Johnson

The Prairie Astronomer 8

breathed heavily. I finally askedwhat he was doing. Pete’s voicecame, not from right behind mebut from over the hill that he wasstill guiding an exposure. Now Idon’t believe in ghosts, especial-ly those that breathe so I turnedaway from my meteor countingto see who was behind me. Noone. At least I didn’t see anyonebut the breathing came from onlya foot or so behind the chair. Ijumped up to see what the heckwas going on. My face went rightinto the snotty nose of a verylarge animal of the bovine clan.My glasses were a mess but I

somehow recovered and while Ionly saw the barest outline of theanimal I decided if Earl couldshoo a cow without a problem socould I.I tried to imitate Earl’s earlieraction but to no avail. It juststood there breathing deeply. Istarted to try again when from fardown the hill I heard Earl’spanicked scream “NO! NO!”Seems he was walking backrather than risk running oversomething again. How he knewwhat was happening I don’t knowbut his urgency stopped me

instantly. He came running upat a sprinter’s speed. Seemshe knew this bovine was a verynasty bull and it would likelyshoo me into the hospital, orworse, if I continued in myQuixotic cause. Earl quicklygrabbed its nose ring and led itback to the pen from which ithad escaped. After I restartedmy heart I also had to restartmy meteor count from thebeginning. Pete continued hisastrophotography withoutmissing a beat. My heartmissed many however.

Note: Mark Dahmke felt that this story needed an accompanying illustration, so heasked cartoonist Paul Fell to capture the moment of Rick's "close encounter."

The Prairie Astronomer 9

A small asteroid that two yearsago flew past Earth at acomfortable distance of about1.3 million miles (2 millionkilometers) will safely fly by ourplanet again in a few weeks,though this time it may be muchcloser.

During the upcoming March 5flyby, asteroid 2013 TX68 couldfly past Earth as far out as 9million miles (14 millionkilometers) or as close as11,000 miles (17,000kilometers). The variation inpossible closest approachdistances is due to the widerange of possible trajectories forthis object, since it was trackedfor only a short time afterdiscovery.

Scientists at NASA's Center forNEO Studies (CNEOS) at theJet Propulsion Laboratory inPasadena, California, havedetermined there is nopossibility that this object couldimpact Earth during the flybynext month. But they haveidentified an extremely remotechance that this small asteroidcould impact on Sep. 28, 2017,with odds of no more than 1-in-250-million. Flybys in 2046 and

2097 have an even lowerprobability of impact.

"The possibilities of collision onany of the three future flybydates are far too small to be ofany real concern," said PaulChodas, manager of CNEOS. "Ifully expect any futureobservations to reduce theprobability even more."

Asteroid 2013 TX68 is estimatedto be about 100 feet (30 meters)in diameter. By comparison, theasteroid that broke up in theatmosphere over Chelyabinsk,Russia, three years ago wasapproximately 65 feet (20meters) wide. If an asteroid thesize of 2013 TX68 were to enterEarth's atmosphere, it wouldlikely produce an air burst withabout twice the energy of theChelyabinsk event.

The asteroid was discovered bythe NASA-funded Catalina SkySurvey on Oct. 6, 2013, as itapproached Earth on thenighttime side. After three daysof tracking, the asteroid passedinto the daytime sky and couldno longer be observed. Becauseit was not tracked for very long,scientists cannot predict itsprecise orbit around the sun, but

they do know that it cannotimpact Earth during its flyby nextmonth.

"This asteroid's orbit is quiteuncertain, and it will be hard topredict where to look for it," saidChodas. "There is a chance thatthe asteroid will be picked up byour asteroid search telescopeswhen it safely flies past us nextmonth, providing us with data tomore precisely define its orbitaround the sun."

For regular updates on passingasteroids, NASA has a list of thenext five close approaches toEarth; it links to the CNEOSwebsite with a complete list ofrecent and upcoming closeapproaches, as well as all otherdata on the orbits of knownNEOs, so scientists andmembers of the media andpublic can track information onknown objects.

For more information on NASA'sPlanetary Defense CoordinationOffice, visit:http://www.nasa.gov/planetarydefense

For asteroid news and updates,follow AsteroidWatch on Twitter:twitter.com/AsteroidWatch

The Prairie Astronomer 10

Annotated

OK most wouldn't consider this5 galaxies "major" but comparedto the others in the image theyare.

This field of 5 galaxies at adistance of about 220 millionlight-years lies in southernPisces only a couple minutes ofarc above Aquarius. The eclipticruns diagonally through theupper right corner of my image.This may account for all the

asteroids the photo bombed theimage.

My main target was MCG -01-60-005. While NED gives it therather normal classification ofSB(s)d it appears more like amess to me. It has a blue blob atthe start of an "arm" at the westend of the bar and another notreally connected to anythingabove the bar a bit east ofcenter. Could this be what's left

of a disturbinggalaxy? Theblue colormay argueagainst this orthe interactioncaused a starburst in thecore. Usuallythese are behind a dust cloud sonot seen in visible light. So thisis unlikely at best but why else isit so disturbed looking? A

5 Major Galaxies, 9 Minor AsteroidsRick Johnson

The Prairie Astronomer 11

couple Tully-Fisher distanceestimates puts it a bit closer at180 million light-years.Considering its redshift prettywell matches the other 4galaxies with redshift data at

NED I think it may be morereliable. I measure it at about75,000 light-years in size.Larger than most galaxies thatlook like it.

While odd looking MCG -01-60-005 has a normal classificationit's just the opposite for IC1501. It looks pretty much like aclassic grand design spiral buthas the classification of

The Prairie Astronomer 12

SAB(s)bc pec: with HIIemission. It too has a redshiftdetermined distance of 220million light-years but its Tully-Fisher measurement says 230million light-years. Again I'll gowith the redshift here. Whatabout it gives it the pec label? Itlooks darned ordinary to me.Must be either in the HII or otherfeatures not seen in visual light.It is a rather large spiral of120,000 light-years in diameter.It was discovered on October19, 1892 by Stephane Javelle.

NGC 7699 is the smallest of theNGC galaxies in this group. It'sredshift distance is 230 millionlight-years. It is shown as SBa?by NED, Sa by the NGC projectand Sa? by Seligman. So is itbarred or not? While my imageshows the star clouds oftenseen at the ends of a bar myresolution isn't sufficient. TheSLOAN image however doesshow a faint bar so I'm goingwith NED on this one. Imeasure its size as 44,000 light-years making it by far thesmallest of the 5. It wasdiscovered by Albert Marth onNovember 18, 1864.

NGC 7700 is an edge on spiralthat NED lists as S0+, Seligmanand the NGC project say S0/a?

and S0-a respectively. Withsuch a prominent dust lane I'dgo with Sa myself. It is 123,000light-years across by mymeasurement. It too S0+wasdiscovered by Albert Marth thatNovember 18th night. Just to itswest is the small round galaxyAPMUKS(BJ) B233154.49-031351.7. It has no redshiftdata so it may be a companionor a distant spherical galaxy. I'dvote for the latter since neithergalaxy looks disturbed in theslightest.

The last galaxy with distancedata is NGC 7701. While it toolooks rather normal for aelliptical like galaxy NEDclassifies it a S0o pec:. While itdoesn't appear peculiar it ispeculiar that the NGC projectsays it is Sb. I hope that's atypo! Seligman says So.Redshift puts it at 230 millionlight-years while Tully-Fishersays 200 million. Using theformer I get a size of just over100,000 light-years. You mightsuspect Albert Marth found it thesame night as the others but thistime William Herschel beat himto it on September 20, 1784.The two Marth found wereapparently too faint forHerschel's scope. Marth used a48" to find the other two. It isn't

in either of the two Herschel 400object observing programs.

For some time now asteroidshave been few and far betweenin my images. Mostly becauseI've been working well awayfrom the ecliptic. While not asconfined to it as the planets theydo usually stick within 20degrees of it and get morecommon as you approach theecliptic. Since the ecliptic runsthough this field it isn't surprisingthere are 9 asteroids noted inthe annotated image. A couplemore should be there but thiswas a very poor night greatlyreducing transparency. Thenine that survived the brightskies and seeing are detailed inthe annotated image.

The poor conditions got farworse when the color data wastaken. It had to be blurred farmore than I like which likelydistorted color of stars seenagainst galaxies. The red datawas so strong compared to blueand green that I suspect the redcolor of NGC 7700 and 7701 istoo strong but I don't likeadjusting features for color soleft them as they came out. Ireally should have tried again forthe color data. It looks "nice"but is highly suspect.

February 11, 2016:

The TMT International Observatory Board of Governors met last week to discuss the future of TMTon Maunakea. To follow is a statement from Henry Yang, Chair of the TMT International ObservatoryBoard:

"At this time, Hawaii remains our first choice for the location of TMT, and we are very grateful for all ofour supporters. Given the enormous investment and potential challenges ahead, it is necessary toalso carry out a review of alternate sites."

News Brief: Thirty Meter Telescope Status

The Prairie Astronomer 13

Saturn's moon Tethys appears to float between two sets of rings in this view from NASA's Cassinispacecraft, but it's just a trick of geometry. The rings, which are seen nearly edge-on, are the darkbands above Tethys, while their curving shadows paint the planet at the bottom of the image.

Tethys (660 miles or 1,062 kilometers across) has a surface composed mostly of water ice, much likeSaturn's rings. Water ice dominates the icy surfaces in the the far reaches of our solar system, butammonia and methane ices also can be found.

The image was taken in visible light with the Cassini spacecraft wide-angle camera on Nov. 23, 2015.North on Tethys is up. The view was obtained at a distance of approximately 40,000 miles (65,000kilometers) from Tethys. Image scale is 2.4 miles (4 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and theItalian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute ofTechnology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington.The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL.The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov andhttp://www.nasa.gov/cassini. The Cassini imaging team homepage is at http://ciclops.org.

The Prairie Astronomer 14

What Happens When LIGO Texts You to Say It’s DetectedOne of Einstein’s Predicted Gravitational Waves

The best thing about a day in mylife on the lookout forgravitational waves is that Inever know when it will begin.

Like many of my colleaguesworking for the LaserInterferometer Gravitational-Wave Observatory (LIGO), themorning of Monday, September14, 2015 caught me completelyoff-guard. For years, we’ve beenjoking that Advanced LIGOwould be so sensitive we mightjust detect one the very first dayit turns on. In retrospect, it’sremarkable how close to realitythat joke turned out to be.

LIGO is listening for gravitationalwaves – one of the lastunproven predictions ofEinstein’s theory of generalrelativity. In his view of theuniverse, space and time arefluid things that depend on anobserver’s frame of reference.For example, time passes just a(very) little bit more slowly forthose who work on the groundfloor of an office building ascompared to their peers on the101st floor. Why? They’redeeper in Earth’s gravitationalpull.

Einstein predicted thatgravitational waves are formedwhen matter and energy warpspace and time. Their effects –

until now unseen – soundbizarre. As a gravitational wavepasses by, an observer will seethe distance between objectschange. All around us space isoscillating, distances arechanging and we are beingstretched and squeezed bypassing gravitational waves.Only the most extreme objects inthe universe can bend spaceenough to produce ripples thatare measurable here on Earth.The effect is so tiny that we failto notice it even with the mostsensitive measurements – butAdvanced LIGO was designedto change all that by directlymeasuring tiny ripples in spaceitself.

Although Advanced LIGO hadcollected data off and on overthe summer of 2015, September14 was slated to be the firstofficial day of its first observingrun. From those who built and

commissioned the advancedLIGO detectors to those whocharacterized and analyzedthe data, we’d all beenpreparing for decades tomake this kind of discovery,but I don’t know if any of uswas truly ready for a detection– and on Day One, as luckwould have it.

Hearing what we werelistening for

Like others on the team, Ishould have been woken upin the middle of the nightwhen LIGO heard that firstgravitational wave – but it wasso early in the run that Ihadn’t even had a chance toenable my text messagealerts! Instead, I read aboutthe event, termed GW150914,on my phone as I walked tocampus hours after it hadbeen observed. It is difficult todescribe the level of

Chad HannaAssistant Professor of Physics,Pennsylvania State University

The Prairie Astronomer 15

anticipation regarding a possibleevent. But I can say that if youhave waited for over 12 years forsuch a discovery, as I have, itcertainly is not something to takelightly when it happens.

Like everyone else at the time,though, I thought this signal wasjust a test of the analysissystem, called a hardwareinjection. I spent the rest of themorning assuming as much. Butminutes before a 2:00 p.m.seminar that same day, wereceived word from each LIGOobservatory that no tests had

been performed. Mystudent, twopostdocs and I allwent to our seminarlooking like we hadseen a ghost! Therest of ourcolleagues inattendance were notpart of LIGO, so wecouldn’t say a word.Our silence stoodfor months to come.

The LIGO ScientificCollaboration (LSC),of which I am amember, is currentlymade up of morethan 1,000 peoplefrom dozens ofinstitutions and 15countries worldwide.There are two LIGOinstruments, one inLouisiana and onein Washington. Andwe work with theVirgo Collaborationthat operates adetector in Italy andthe GEO600

detector team in Germany.Since we are all so far apart, wemet by teleconference so folkswho are at the observatories andfolks who are analyzing the datacould alldiscuss whatwas happeningand whether ornot to share theinformationmore broadly.

At first it wasunclear whichof manypossibilities

could be responsible for theGW150914 signal. It wouldhave to be a majorastronomical event thatreleased immense amounts ofenergy – such as a binarymerger, a nearby supernovaor some completelyunforeseen occurrence. Initialinvestigations indicated that itcould be a binary black holemerger – two black holes thatare driven to smash togetheras they release energy in theform of gravitational waves.

Over the next few weeks, weworked to assess thesignificance of GW150914. Itsprobability of being the realthing was simply off the chartsand had virtually no plausibleexplanation as anything but agravitational wave. There wasjust no way random noisecould have caused such aloud, consistent signalbetween detectors thatmatched the expectation ofgeneral relativity so perfectly.

From then on, thecollaboration shifted into highgear, preparing additionalscientific publications toprovide all the juicy detailsabout the detection and

These plots show the signals of gravitationalwaves detected by the twin LIGOobservatories at Livingston, Louisiana, andHanford, Washington. The signals came fromtwo merging black holes, each about 30 timesthe mass of our sun, lying 1.3 billion light-years away. LIGO, CC BY-ND

The Prairie Astronomer 16

interpretation of GW150914. Wenow know that gravitationalwaves can be measured, binaryblack holes exist and that thereare perhaps far more detectablesources of gravitational wavesthan we had anticipated.

LIGO logistics

GW150914 stretched andsqueezed our nearby space byabout 1 part in 1021. This isequivalent to squeezing theentire Milky Way galaxy by atypical person’s height. As youmight imagine, it is nearlyimpossible to measure such asmall change in distance. To doso, LIGO uses high-powerlasers, ultra high vacuum andsome of the most advancedoptics ever built.

The basic idea is simple: LIGOhas two 4-km-long arms built at90 degrees with respect to oneanother. A high-power laserbeam is split in two to traveldown each arm separately.When the laser gets to the end,it’s reflected back by a mirror. Ifone arm is longer than another,due to the change in spacecaused by a gravitational wave,then the laser light won’t arriveback at the same time in eacharm.

We continuously record therecombined laser light; itencodes how the gravitationalwave causes space to stretchand squeeze at frequencies thatare very similar to what thehuman ear can hear. That’s whywe often think of LIGO aslistening to the universe. In fact,LIGO records its data as what’sbasically an audio file. You canliterally listen to the gravitationalwaves detected with LIGO usingheadphones.

Colliding black holes andneutron stars are some ofLIGO’s primary targets, thoughwe also search for supernovae,spinning isolated neuron starsand gravitational waves left overfrom the birth of the universe.The LIGO detectors, for themost part, are sensitive tosources all over the sky, whichmeans a single detector can’t tellfrom which direction agravitational wave arrived.However, using multipledetectors we can localize thesource. All the gravitationalwave detectors across the globework together to makeobservations of the same signalsat the same time (within tens ofmilliseconds).

I’m part of a team that issearching for merging neutronstars and black holes in nearreal time. We hope to knowwithin seconds that agravitational wave has reachedthe Earth. With this knowledge,we can inform otherastronomers who can point theirtelescopes in the direction of theevent in the hope that thegravitational wave will have anelectromagnetic counterpart.Having information from both

channels is a bit like havingboth sound and picture whenwatching a film. The moviewould be far less interestingwith only one and not theother.

Unlike many telescopes,LIGO can observe at any timeof day, though it is sensitive toenvironmental noise that’soften caused by humanbeings working nearby.Observing at night tends to beeasier, when most people arein bed. The team I work withis always on call. If agravitational wave event isdetected, we should knowwithin a minute and receive acall to our cellphones as wellas a text message with detailsabout the event – just ashappened on September 14.

Beginning of a new era

Detecting this firstgravitational wave event haschanged the world. It confirmsthe last great prediction of arevolutionary theory that’snow over 100 years old. But itdoesn’t stop there. We’re stilllistening for more gravitationalwaves; soon Advanced LIGOwill detect them regularly –

The Prairie Astronomer 17

This is a partial list of objects visible for theupcoming month.

Planets

Jupiter: Reaches opposition on March 8th atmagnitude -2.5 with a disk 44” wide.Uranus: By mid-March it will be too low forobservation.Neptune: Not visible this month.Mars: Rises around midnight and increases inbrightness from 0.3 to -0.5 at months end.Saturn: In southern Ophiuchus at magnitude 0.5with a disk 17” wide. The rings are tilted 26° fromedge on with a span of 38”.Venus: Rises an hour before the Sun at itsmaximum magnitude for the year at -3.8.Mercury: Reaches superior conjunction onMarch 23rd and is not visible this month.

Messier List

M41: Open cluster in Canis Major.M44: The Beehive Cluster in Cancer.M46/M47: Open clusters in Puppis.M48: Open cluster in Hydra.M50: Open cluster in Monoceros.M67: Open cluster in Cancer.M81/M82: Galaxy pair in Ursa Major.M93: Open cluster in Puppis.Last Month: M1, M35, M36, M37, M38, M42,M43, M45, M78, M79Next Month: M40, M65, M66, M95, M96, M105,M106, M108, M109

NGC and other Deep SkyObjects

Melotte 71: Open clusterPuppis.NGC 2423: Open clusterin Puppis.NGC 2438: Planetarynebula within M46 inPuppis.NGC 2440: Planetary nebula in Puppis.NGC 2672: Galaxy in Cancer.NGC 2775: Galaxy in Cancer.

Double Star Program List

Epsilon Canis Majoris: Bright white and paleblue pair.Delta Geminorum: Wasat, yellow and pale redstars.Alpha Geminorum: Castor, White primary with ayellow secondary.12 Lyncis: Close yellow-white pair.19 Lyncis: White pair.38 Lyncis: White and yellow stars.Zeta Cancri: Yellow primary with a pale yellowsecondary.Iota Cancri: Yellow and pale blue pair.

Challenge Object

NGC 2749: The brightest member in a galaxygroup in Cancer. Other galaxies include NGC2744, NGC 2751, and NGC 2752.

March Observing: What to ViewJim Kvasnicka

and each one will tell ussomething new about theuniverse.

As observations becomecommonplace, we will enter a

new era of gravitational waveastronomy and start to map outjust how black holes and neutronstars are born, evolve andeventually die. Someday wemight even be surprised to

detect something we neverexpected. From now on,every time my phone rings,that’s what I will be hoping for.

The Prairie Astronomer 18

Puppis

Puppis, the Ship’s Stern, was once part of theancient Greek constellation Argo Navis, the Ship.Due to its size it was divided in the 1750’s intoPuppis, the Ship’s Stern; Pyxis, the Compass;Vela, the Sails; and Carina, the Keel. Puppisalone still covers 673 square degrees. Puppis iseast and southeast of Canis Major and it containsan exceptionally star-rich portion of the MilkyWay. Because of this Puppis is rich in openclusters including three Messier objects in M46,M47, and M93. The open clusters in Puppis varya great deal. Several are large and loose, someare large and rich and a number are faint andrequire a medium to large telescope to be seen.The constellation Puppis is best seen in March.

Showpiece Objects

Open Clusters: M46, M47, M93, NGC 2477,NGC 2539Planetary Nebulae: NGC 2438, NGC 2440,NGC 2452

Mythology

In Greek mythology the ship Argo was the vesselcommanded by Jason and his fifty Argonauts insearch of the Golden Fleece. When theyreturned with the Fleece, Athens commemoratedthe event by placing the ship Argo in theheavens.

Number of Objects Magnitude 12.0 andBrighter

Galaxies: 7Open Clusters: 46Planetary Nebulae: 3Globular Clusters: 1

Focus on Constellations: PuppisJim Kvasnicka

Photo: Till Credner - Own work: AlltheSky.com

The Prairie Astronomer 19

The Closest New Stars to EarthEthan Siegel

When you think about the newstars forming in the Milky Way,you probably think of the giantstar-forming regions like theOrion Nebula, containingthousands of new stars withlight so bright it's visible to thenaked eye. At over 400 parsecs(1,300 light years) distant, it'sone of the most spectacularsights in the night sky, and thevast majority of the light fromgalaxies originates fromnebulae like this one. But itsgreat luminosity and relativeproximity makes it easy tooverlook the fact that there area slew of much closer star-forming regions than the OrionNebula; they're just much,much fainter.

If you get a collapsing

molecular cloud many hundredsof thousands (or more) timesthe mass of our sun, you'll get anebula like Orion. But if yourcloud is only a few thousandtimes the sun's mass, it's goingto be much fainter. In mostinstances, the clumps of matterwithin will grow slowly, theneutral matter will block morelight than it reflects or emits,and only a tiny fraction of thestars that form—the mostmassive, brightest ones—willbe visible at all. Between just400 and 500 light years awayare the closest such regions toEarth: the molecular clouds inthe constellations ofChamaeleon and CoronaAustralis. Along with the Lupusmolecular clouds (about 600light years distant), these dark,

light-blocking patches arevirtually unknown to most skywatchers in the northernhemisphere, as they're allsouthern hemisphere objects.

In visible light, these cloudsappear predominantly as darkpatches, obscuring andreddening the light ofbackground stars. In theinfrared, though, the gas glowsbrilliantly as it forms new starsinside. Combined near-infraredand visible light observations,such as those taken by theHubble Space Telescope, canreveal the structure of theclouds as well as the youngstars inside. In the Chameleoncloud, for example, there arebetween 200 and 300 newstars, including over 100 X-ray

This article is provided by NASA Space Place.With articles, activities, crafts, games, and lesson plans, NASA SpacePlace encourages everyone to get excited about science and technology.Visit spaceplace.nasa.gov to explore space and Earth science!

Image credit: NASA and ESA Hubble Space Telescope. Acknowledgements: Kevin Luhman(Pennsylvania State University), and Judy Schmidt, of the Chamaeleon cloud and a newly-formingstar within it—HH 909A—emitting narrow streams of gas from its poles.

The Prairie Astronomer 20

From the Archives: July, 1968

Possibly the shortest PAC newsletter ever - a postcard.

sources (between theChamaeleon I and II clouds),approximately 50 T-Tauri starsand just a couple of massive,B-class stars. There's a thirddark, molecular cloud(Chamaeleon III) that has not

yet formed any stars at all.

While the majority of new starsform in large molecular clouds,the closest new stars form inmuch smaller, more abundantones. As we reach out to the

most distant quasars andgalaxies in the universe,remember that there are stillstar-forming mysteries to besolved right here in our ownbackyard.

The Prairie Astronomer 21

To check out one of the club telescopes, please contacta club officer. Scopes can be checked out at a regularclub meeting and kept for one month. Checkout canbe extended for another month if there are no otherrequests for the telescope, but you must notify a clubofficer in advance.100mm Orion refractor: Checked out to Beth J.10 inch Meade Dobsonian: Available13 inch Truss Dobsonian: Available

CLUB MEMBERSHIP INFOREGULAR MEMBER - $30.00 per year. Includesclub newsletter, and 1 vote at club meetings, plus allother standard club privileges.

FAMILY MEMBER - $35.00 per year. Same asregular member except gets 2 votes at clubmeetings.

STUDENT MEMBER - $10.00 per year withvolunteer requirement.

If you renew your membership prior to your annualrenewal date, you will receive a 10% discount.

Club members are also eligible for specialsubscription discounts on Sky & TelescopeMagazine.

CLUB TELESCOPES

CLUB APPARELOrder clubapparel fromcafepress.com:

Shop through AmazonSmile to automaticallydonate to PAC:

CLUB OFFICERSPresident Jim Kvasnicka

(402) 423-7390jim.kvasnicka@yahoo.com

Vice President Brett Bollerproboller86@yahoo.com

2nd VP(ProgramChair)

Beth Jenckesbeth.jenckes@yahoo.com

Secretary Lee Taylorotaylor88@gmail.com

Treasurer John Reinertjr6@aol.com

Club ObservingChair

Jim Kvasnickajim.kvasnicka@yahoo.com

OutreachCoordinator

Dan Delzelldan@delzell.net

Website andNewsletterEditor

Mark Dahmkemark@dahmke.com

The Prairie Astronomer is published monthlyby the Prairie Astronomy Club, Inc.Membership expiration date is listed on themailing label. Membership dues are: Regular$30/yr, Family $35/yr. Address all newmemberships and renewals to: The PrairieAstronomy Club, Inc., PO Box 5585,Lincoln, NE 68505-0585. For other clubinformation, please contact one of the clubofficers listed to the right. Newslettercomments and articles should be submitted to:Mark Dahmke, P. O. Box 5585, Lincoln, NE68505 or mark@dahmke.com, no less than tendays prior to the club meeting. The PrairieAstronomy Club meets the last Tuesday ofeach month at Hyde Memorial Observatory inLincoln, NE.