There are many resources created for your visitors at your outreach events. However, these cards are created as a
reference for you, the host. Use them if you:
• arenewtopublicoutreachandaren’tsurewhattosay• arelookingforanewwaytoexplainsomeofthesameobjects
you’vebeentalkingaboutforyears.
Give your visitors a new perspective on the wonders of the sky.
Connect with the exciting science of exoplanets! Cardsincludedfor:doublestars,galaxies,globularclusters,moons,openclusters,planetarynebulae,planets,redstars,starswithplanets,starnurseries,andsupernovaremnants.
OBSERVING CARDS
National Aeronautics and Space Administration
The narratives give you - the sky guide - stories to inspire the public at the telescope and beyond.
Share the pictures with visitors to illustrate points.• Prepare yourself: Think about what you might be observing
tonight. Pick one of the anecdotes to try.• Prepare your visitor: While the eyepiece is occupied, talk to the
next person in line. • Listen: Often people ask, “How big?” and “How far?” because
they don’t know what else to ask. By opening with a story, you encourage relevant questions. This also allows you to read your visitors’ interests and knowledge levels.
• Give Context: Most people have no concept of the distance involved in a light-year or how long a billion years is. Stories engage visitors with a personal connection to the objects you’re sharing. Distances are included here in light-years (ly), millions of light-years (Mly), astronomical units (AU), and Earth diameters (DEarth).
These cards complement the Celestial Treasure
Hunt Handout.
Findversionsofthesecardsformobiledevices,plushandouts,presentations,andmorefromtheNightSkyNetworknightsky.jpl.nasa.gov
Keep these with your telescope
TIPS FOR THE CARDS
Thissymboldirectsyoutostoriesthatconnectthenightskywiththesearchforexoplanets.NASA’sPlanetQuestaimstoanswerthebigquestion:Are we alone?
planetquest.jpl.nasa.gov
© 2013 Astronomical Society of the Pacific Educational use encouraged
DOUBLE STARS
LeotheLion Algieba
Regulus
Mizar
“BigDipper”
Alcor
Albireo
CygnustheSwan
Altair
Deneb
Vega
Cygnus’Albireoappearsasanicelycontrastingblueandayellowdoublestar.Theyellowstarisanotherdouble,butrequiresaverypowerfultelescopetoobserve.TheDoubleDoublelieswithinabinocularviewofbrightVega.
MizarandAlcor,doublestarsintheBigDipper,canbeseenbythosewithkeeneyesight.ThereisanArabicsaying,“HecanseeAlcorbutnotthefullMoon.”It’ssimilartothecontemporarysaying,“Hecan’tseetheforestforthetrees.”
AlgiebainLeo’smaneisadouble-starsystemwithagasgiantplanetorbitingthelargerstar.
Double Double Lyra
theHarp
Scientistshaveevenfoundsomeplanetsthatorbitbothstarsinabinarysystem.Anartistimaginesthesunsetbelow.NASA/AmesResearchCenter/KeplerMission
National Aeronautics and Space Administration
Mizar and Alcor in the Big Dipper, best in Spring and Summer:Theabilitytoseebothofthesestarsisalmostidenticaltotestsfor20/20vision.Dist: 82 ly
TheSummerTrianglehostsmanydoubles,includingcolorfulAlbireo in Cygnus, Dist: 430 ly,andeLyr,theDouble DoubleinLyra,Dist: 160 ly,wherethebrightest2starsappearinbinocularsandlargertelescopesresolveall4stars.
Algieba (al-jee-bah) in Leo, Spring:Bothoftheselargestarsarenearingtheendoftheirlives.Itdoesn’tbodewellfortheplanetorbitingthelargerstar.Dist: 130 ly
DOUBLE STARSEXAMPLES OF DOUBLE STARS
Twice the fun!
Planetshavebeenfoundarounddoublestars.Imaginelivingonaplanetorbitingadoublestar.Youcouldhave2shadows!Woulditevergetdark?
Whylimititattwo?Starscomeinevenlargerconfigurations.Polaris,theNorthStar,isa3-starsystem.
IfEarthhadformedaroundacoolerredstar,oureyesmayhavedevelopeddifferentlybecausecoolstarsemitmoreinfraredlightthanourSundoes.Maybewecouldseeinfraredlightinsteadofthecolorsoftherainbow.
Adifferenceincolormeansadifferenceintemperature.BluestarsarehotterthanourSun,redstarscooler.Wouldaplanetaroundahotbluestarneedtoorbitnearerorfartherawaythanourorbittostaywarmbutnothot?
It’scommonforstarstocomeinpairsbutthey’renotoftenidenticaltwins.Doublestarsofdifferentsizesandcolorsbeautifullyillustratethevarietyofourstellarneighbors.
Imagine planets seeing double
Somestarsonlyappeartobedoubles,butaren’t“truebinaries.”Theymaybeveryfarapartbutlieonthesamelineofsightfromourperspective.
Castor in Gemini, Winter:BothoftheheadsofthetwinsofGeminiaredoublestars.EachofCastor’scomponentstarsaredoubles,too.Dist: 50 ly
WallyPacholkaastropics.com
GALAXIES
SeeingtheSombreroedge-onhelpsnewobserversbetterunderstandtheirviewofourownMilkyWay.NASA/STScI/AURA
NotetheWhirpoolGalaxy’sspiralarmsandcompanion.NASA/ESA
Earthisoneofbillionsofplanetsaroundbillionsofstarsinourgalaxy.AndtheMilkyWayisjustoneofbillionsofgalaxies!
Thenearestlargegalaxy,Andromeda,canevenbe
seenwithoutatelescope.
TheVirgoClustercontainsthousandsofgalaxies,includingegg-shapedgalaxieslikethese.(M84andM86).NOAO/AURA/NSF
National Aeronautics and Space Administration
Bode’s Galaxy (M81), Spring/Summer:Thisisagreatfirststar-hoppingtargettofindinbinocularsorasmalltelescope.Seeifnewbiescanalsofindthethinstarburstgalaxynearby(M82).Dist: 11.7 Mly
Andromeda (M31), Autumn:IftheMilkyWaywerethesizeofaCD,Andromedawouldbeasbigasadinnerplate.Atthatscale,they’dbeabout8feetapart.Dist: 2.5 Mly, ~1 trillion stars
Whirlpool (M51), Winter/Spring:Isactuallyapairofinteractinggalaxies!Dist: 23 Mly
Sombrero (M104), Spring:Seenedge-on,thisspiralgalaxyisontheedgeofagalaxycluster,thoughnotpartofit.TheVirgoClusterofgalaxiesisfullofmanytypesofgalaxies,includingellipticals.Dist: 29 Mly
GALAXIESEXAMPLES OF GALAXIES
Looking up, galaxies are the most distant objects we can see.
Wecan’tseethewholeMilkyWaybecauseweareinthemiddleofthedisk-justlikewecan’tseeourwholetownfromourporchatnight,justthelightsnearestus.Doyouthinkanyofthoseneareststarsmightincludeaplanetorbitingit,withlifeonit,lookingbackatus?
Ifwewanttogetanideaofwhatourgalaxymightlooklikefromabove,wecanlookatothergalaxies.Therearemanytypes.Weliveinaspiralgalaxy,butsomegalaxieslooklikeeggsorspheresandsomehaveirregularshapes.
Moststarsprobablysupportplanets.Beyondallthestarsinourowngalaxy,lookatthatgalaxyfullofstars!Imaginethealienpossibilitieswithallthoseworlds.
TherearehundredsofbillionsofgalaxiesintheUniverse.Eachgalaxyconsistsofmillionstobillionsofstars.ThatmeanstherearemorestarsintheUniversethanallthegrainsofsandoneverybeachintheworld!
Galaxies have planets aplenty!
GLOBULAR CLUSTERSM13,theGreatHerculesGlobular,isoneofthefinestyou’llobserve.In1974thefirstradiomessageaboutEarthwassentintoouterspacefromtheAreciboObservatory.Itwaspointedinthedirectionofthisglobularcluster.Itsjourneywilltakemorethan25,000years.Ouraimwasabitoff;bythetimethemessagearrives,theclusterwillhavemoved!Anyway,wehavefoundveryfewplanetsinglobularclusters.Canyouthinkofcloserplacestosendanalienmessage?ESA/Hubble and NASA
Globularclustersorbitourgalaxy(illustrationofasideviewhere)liketightswarmsofbees.Theyarenottypicallyinthediskofthegalaxy,unlikemostMilkyWayobjectsthatweobserve.
globular clusters
Sun’s location
100,000 light-years
halo
bulge
1,000 light-years
disk28,000 light-years
National Aeronautics and Space Administration
Small, old, and far away, so what?
Hercules Cluster (M13), Spring: Hasabout300,000stars,asmanystarsasallthehairson3people’sheads!Dist: 25,000 ly
M79 in Lepus, Winter:Thisisoneoffewglobularclustersseeninwinter,whenwefaceawayfromthegalacticcenter.Dist: 41,000 ly
Scorpius Cluster (M4), Summer: Relativelysmall,itonlyhasabout10thousandstars.ItisaveryeasyclusterfornewstarhopperstofindbecauseitisclosetothebrightstarAntares. Dist: 7,000 ly
GLOBULAR CLUSTERSEXAMPLES OF GLOBULAR CLUSTERS
In a globular cluster, many stars are packed into a small space. Imagine the view from inside a globular cluster.
Globularclustersaren’tactuallysmall,theyarejustmuchfartherawaythananythingelseweobserve,exceptothergalaxies.
StarsinglobularclustersaresomeofthefirststarstohaveformedintheMilkyWay.Someclustersevenformedindifferentgalaxiesandwerestolenduringpastinteractions.
Inthecenter,itwouldnevergetdark.Therearesomanystarsthatevenatnightitwouldnevergetdark.Imaginedozensofbrilliantstarsforeverystaryouseetonight!
CouldwelookbackattheMilkyWayandseeourSun?No,itwouldbeliketryingtopickoutyourporchlightonamapoftheUSatnight!
IfyouwereontheedgeoftheclusterclosesttoEarth,allofthecluster’sstarswouldbeinonehalfoftheskyandtheotherhalfwouldbelitupwiththehazyMilkyWay.
M22 in Sagittarius, Summer:Justabovethetipofthe“Teapot,”thisisaneasyfind.Dist: 10,000 ly
M5 in Serpens, Summer:Thisisoneofthefinestglobularclustersinsmalltelescopes.Dist: 25,000 ly
Hailedasoneofthebestsciencefictionstoriesofalltime,IsaacAsimov’s“Nightfall”tellsofasocietylivingonaplanetinaglobularcluster.
MOONS
Saturn’sEnceladusspraysjetsofwaterfromitssouthpole.Credit: NASA/JPL
PicturedtoscalearephotographsofEarthanditsMoon,Jupiter’sfourlargestmoons,sevenofSaturn’smoons,Neptune’slargestmoon(Triton),threeofUranus’moons,andPluto’slargestmoon(Charon).NASA
Exoplanetsinhabitablezonesoftheirparentstarscouldhaverockymoons.Anartistimagineshabitableexomoons.Credit: NASA/JPL-Caltech
Dione
Mimas
Rhea
Titan
Enceladus
Saturn’sIapetus
Europa
IoGanymede
Jupiter’sCallisto
EarthandEarth’sMoon
Pluto’sCharon
Oberon
Uranus’TitaniaMiranda
Neptune’sTriton
Tethys
National Aeronautics and Space Administration
Jupiter’s Moons: GalileodiscoveredJupiter’sfourlargemoons.WenowknowthesemoonsaremuchmoreactivethanEarth’sMoon,hostingvolcanoes(Io),ice-coveredoceans(Europa),andamagneticfield(Ganymede,largestmoonintheSolarSystem).Dist: ave. 500 million miles (800 Mkm), or 30 light-min. (4.2 - 6.2 AU)
Earth’s Mooniscoveredwithcraters,easilyvisiblethroughbinoculars.EarthwashitbyevenmoreasteroidsandcometsthantheMoon,butwehaveanatmosphereandactivecrustthaterasedmostpastimpacts.Distance: 238,900 miles (384,400 km) or 1.4 light-sec.
MOONSEXAMPLES OF OUR SOLAR SYSTEM’S MOONS
Earth’s Moon - our most distant human exploration
CanweseetheflagontheMoonthroughourtelescope?No,thesmallestfeaturewecanseethroughmosttelescopesisaboutamile(or2km)across.
Saturn’smoonTitanhasathickatmosphereandlakesofmethane.WithworldslikeSaturn’smoonsnearby,imaginewhatwemightsomedayfindonexoplanetmoons.
Whilemoonsaroundexoplanetsarestillveryhardtodetect,imaginethepossibilitiesifgasgiantplanetscouldhosthabitablemoons.Seeanartist’sideaofaworldlikethisontheotherside.
Exoplanet moons expand the possibilities
OurMoonwasoncemuchclosertoEarth.Itismovingawayfromusataboutthesamerateasourfingernailsgrow-aboutaninchandahalf(3.8cm)ayear.
Earth’sMoonisthefarthestthathumanshavevoyaged.NeilArmstrong’sfootprintsarestillthereandwillremainthereformillionsofyears.There’snowindontheMoontoblowitaway.
AlllifeonEarthrequireswatertosurvive,soscientistslookforwateryworldswhensearchingforpossiblelifebeyondEarth.Saturn’smoonEnceladushasjetsofwater,evidenceofanoceanbeneathitsicysurface.Seeimage.
OPEN CLUSTERSAlargeamountofwarmdustfoundorbitingthestarHD23514inthePleiadesstarclustersuggestsacollisionoftwoEarth-sizedbodies.Credit: Gemini Observatory/Lynette Cook
ScientistsarefindingplanetsaroundSun-likestarsinopenclustersliketheBeehive.WecanfindtheBeehiveClusterbetweenthetwobrightstars,RegulusandPollux.
Orion’sBelt
Hyades
Pleiades
Openclustersvaryinappearance,asseeninthecontrastabovebetweentheWildDuckCluster(left)andthePleiades(right).Credit: Rawastrodata
Cancer
Regulus
Pollux
Castor
BeehiveCluster
TwoclustersthatareeasytospotindarkskiesaretheHyades,orheadofTaurustheBull,andthenearbyPleiades,alsoknownastheSevenSisters.JustfollowthelineofOrion’sBeltasseenontheright.
National Aeronautics and Space Administration
Hyades, Winter:TheclosestopenclustermakesalargeVshape(Aldeberanisnotpartofthecluster).Dist: 151 ly
Pleiades (M45), Winter:ThePleiadesstarswerebornwhilethedinosaurswereroamingtheEarth–about100millionyearsago.Thisclusterhappenstobedriftingthroughacloudofgas-nottheonefromwhichitwasborn.Dist: 424 ly
Beehive (M44), Spring: Thisisaneasyfirststar-hoppingtargetwithbinoculars.FinditbetweenPolluxandRegulus.Dist: 570 ly
Wild Duck (M11) in Scutum, Summer/Autumn: Oneoftherichestclusters.Doesitlooklikeaflockofducksinflighttoyou?Dist: 6,200 ly
OPEN CLUSTERSEXAMPLES OF OPEN CLUSTERS
Meet some of our newest neighbors, stars in open clusters.
Whileglobularclustersandopenclusterssoundsimilar,theyareverydifferentinnumberandage.Globularclusterscanincludehundredsofthousandsofveryoldstarsboundinatightswarm.Inroughlythesameamountofspace,anopenclustermayhavejust100orsoyoungstars.
Starsinopenclustersarebright,young,andoftenblue-theteenagesistersofstars.They’veblownofftherestoftheirparentalgasanddustandhangtogether.Eventuallythestarsdriftapart,butfornow,theytravelinapackthroughtheirneighborhood(spiralarm).
Planetsorbitingnewstarswithinopenclusterslikelyliveverychaoticlives.Theyhavenotyetformedstableorbitssocollisionsoccuroften.WhileourSunwasstillinanopencluster,aMars-sizedplanetprobablyslammedintoEarth,eventuallycreatingourMoon.
Thenewly-formedstarsinanopenclusterwerebornfromthesamecloudofgasanddust.Thehazethatsurroundedthematbirthhasblownawayandyoucanseetheindividualstars.
Planets forming around new stars
PLANETARY NEBULAELargeimagesbelowaretakenwithprofessionaltelescopes,oftenfromspaceandusingspecialfilters.Thesmallerimagesgiveabetterideaofwhatyoucanexpecttoseethroughatelescope.Filtersonsmalltelescopescanalsobringoutfeatures,asseenhereinthecenterimagesbyOleNielsen.
Ring Nebula as seen by Hubble - NASA, ESA, and C. Robert
O’Dell (Vanderbilt University)
Ghost of Jupiter as seen by Hubble - HST/NASA/ESA
Eskimo Nebula as seen by Hubble - NASA/Andrew Fruchter
(STScI)
Dumbbell Nebula as seen by the Very Large Telescope (ESO)
National Aeronautics and Space Administration
Ring Nebula (M57), Summer/Autumn:Weseethisnebulafromthetopofitscylindricalshape.Ifwecouldseeitfromtheside,itwouldlooklikearectangle.Fromanangle,itwouldlikelylookmoreliketheDumbbell.Dist: 2,300 ly
Dumbbell Nebula (M27), Summer:Someobserversthinkitlookslikeanapplecore.Thislargenebulaspreadsoutovermorethan4light-years.Dist: 1,300 ly
Eskimo Nebula, best viewed in Winter/Spring:Noticethebrightcentralstarpuffingoffitsouterlayers.Doestheoutershelllooklikeaparkatoyou?Dist: 3,000 ly
PLANETARY NEBULAEEXAMPLES OF PLANETARY NEBULAE
From red giant to white dwarf in a few puffs
Planetarynebulaehelpenrichthegalaxywithelementslikecarbonandnitrogen.Theseelementsmayeventuallybeincorporatedintheseedsofnewplanetsinthenextcycleofstarbirth.SomeofEarth’scarbonandnitrogenmayhavecomefromaplanetarynebula.
Theplanetarynebulaphaseofastar’sliferepresentsashortbutimportanttimeinthelifeofstarsupto8timesthemassofourSun.IfwecomparedthatperiodinaSun-likestar’slifetoahumanlifetime,itwouldcorrespondtoaboutthelasthourofourlife.Thewholedisplayfadesintothegalaxyinabout10,000years.
Thename“planetarynebula”isamisnomer.Itwasgiventothisclassofobjectbecausetheyappearsmall&roundandpossiblyplanet-likethroughprimitivetelescopes.Itwasveryquicklyrecognizedthatthesewerenotplanets,butthenamestuck.
Ghost of Jupiter Nebula, Spring:Likemanyplanetarynebulae,thisoneappearsgreenishandnotquiteround.Greenisthecolorhumansseebest,whichisluckybecauseitisfaint.Dist: 1,400 ly
What does a planetary nebula have to do with planets?
PlanetarynebulaearetheswansongsofstarslikeourSunaftertheredgiantstage.Theypuffofftheirouterlayers,collapse,andslowlycooloffasawhitedwarf.
PLANETSVenusisclosertotheSunthanweare,givingusdifferentviewsofthehalf-litsphereovertime.
Saturn’sringsareprobablypiecesofcrushedasteroidsandcomets,rangingfromsugar-tohouse-sized.
Comparesizes(notdistances)oftheSunandplanetsinourSolarSystem.
ThevisiblefeaturesonJupiteraremostlyammoniaclouds.
RoversonMarsgivegreatviews,butonlyseeasmallportionoftheplanet.ImaginetryingtolearnallaboutEarthfromagolfcart.
National Aeronautics and Space Administration
Saturn:Saturn’sdaysareonlyabout10hourslong.Thisrapidspinningcausestheplanettobulgearoundtheequator.Dist. from Sun: 9.6 AU, Diameter: 9.1 DEarth
Venus:NamedfortheRomangoddessofloveandbeauty,Venuswouldnotbeagoodchoiceforaromanticgetaway.Itssurfaceishotenoughtomeltleadandithasacrushingatmosphereofcarbondioxidewithcloudsofsulfuricacid.Dist. from Sun: 0.7 AU, Diameter: 0.95 DEarth
Mars: Theplanet’sreddishhueiscausedbyrustonthesurfaceanddustintheatmosphere.MissionstoMarsrevealgreatchannelsandfloodplains,likelycarvedbyancientwater.Dist. from Sun: 1.5 AU, Dia: 0.53 DEarth
Jupiter:Thisgasgiantformsasortofminiaturesolarsystem,includingmanymoonsandamagneticfield,buttheplanetdidnotgrowbigenoughtobecomeastar.Itwouldhaveneededabout80timesmoremassforthis.Dist. from Sun: 5.2 AU, Diameter: 11 DEarth
PLANETSEXAMPLES OF PLANETS
The ancients’ “wandering stars” are today’s laboratories
OurSolarSystemdividesnicelyintofourregions:theinnerrockyplanets,theAsteroidBelt,thegasgiantplanets,andfinallythesmallicybodiesbeyond.Untilwebegandiscoveringplanetsaroundotherstars,wethoughtallplanetarysystemsmightlooksomethinglikethis.Wewerewrong.SeeStars With Planets card.
Theplanets,Sun,andMoonallpassinfrontofthestarsofthezodiac.That’swhytheseconstellationswereimportanttoancientcultures.WhilewehaveknownaboutthedanceofSun’splanetsformillennia,findingexoplanetsaroundotherstarshasrecentlyexpandedhumanity’sviewofourplaceintheuniverse.
Astronomersaresearchingforrockyexoplanetsorbitingwithinthehabitablezonesofotherstars.IntheSolarSystemonlyEarthhasliquidwaterintheSun’shabitablezone,butchangesintheatmospheresofVenusandMarscouldmakethemhabitableaswell.
RED STARS
ThinkofhowbigandimportantourSunistous.NowcomparetheSuntoaredgiant(right).Evenmoreastoundingisthesizeoftheredsupergiants.Onthescaleshownontheright,starslikeBetelgeusewouldbeastallandwideasanadultstandingwitharmsoutstretched.
The Sun will eventually become a red giant,
expanding and likely engulfing the inner rocky
planets.
If we shrink the Sun to the size of a tiny pebble...
However,thereisevidenceofplanetssurvivingthegiantstage.Here,anartistimaginesaplanetorbitingdangerouslyclosetoaredgiantstar.Credit: NASA
a red giant would be about as big as this card.
Whenstarsexpand,theymayconsumetheplanetsorbitingthem.Artist’s impression by James Gitlin/STScI
National Aeronautics and Space Administration
Betelgeuse, Winter:ThisbrightstarformedmillionsofyearsagoinOrion’sBelt.Centuriesago,Chineseastronomersrecordedthatthisstarwasyellow,beforeitcooledtoitspresentredcolor.Dist: 650 ly.
Arcturus, Summer:Thisbrightstarwascalledthe“starofjoy”byancientPolynesiansailors.IthelpedthemnavigatethelongdistancetoHawaii.Dist: 37 ly
RED STARS
Red giants are dying stars, cooling down and puffing up
Notallredstarsaregiants.Infact,mostofthestarsinourgalaxyareredandsmall.Thesereddwarfsareallaroundus,makingupabout3/4ofthestarsinourgalaxy.However,theyaresodimthatnonearevisiblewiththeunaidedeye.ThesestarsarestableformuchlongerthanSun-likestars.Theyalsohostplanets,sotheymaybegoodplacestolookforadvancedlifeforms.
OurSunwillbecomearedgiantinabout5billionyears.Markyourcalendars!Whenthathappens,itwillgetsobigitcouldengulfMercury,Venus,Earth,andmaybeevenMars.In2012,astronomersdetectedarockyexoplanetbeingdevouredbyitsstar.
Redsupergiantsarelargerbyfarthantheredgiant(seecomparison,reverse).Thesedyingstarsaresolargethattheywillendtheirlivesinamassivesupernovaexplosion.Whenthathappens,itwillbesobright,we’llbeabletoseethemduringtheday!Butdon’tworry,theyposenodangertous.
Asstarsuseupalloftheiravailablefuel,theybecomecoolerandexpand,enteringthegiantphase.ForastarlikeourSun,thisphasecanlastabout10%ofitslifetime,orabillionyears.
Aldebaran, Spring:ItappearstobepartoftheV-shapedHyadesclusterbutinfactismuchclosertousthanthosestars.Dist: 65 ly
RED GIANTS
Exoplanet eaters and dwarfs
RED SUPERGIANTS
Herschel’s Garnet Star (Mu Cephi), Autumn:ThisstarissolargethatifitreplacedourSun,itwouldextendallthewaypastJupiter.Dist: 6,000 ly
STAR NURSERIES
Anartistimaginesastarwithplanetsforminginthedepthsofastarnursery. Credit: NASA/JPL-Caltech
HubblespottedthesenewstarsintheOrionNebula.Theyaresurroundedbygasanddustintheprocessofbecomingplanets,called“protoplanetarydiscs.”Credit: NASA, ESA and L. Ricci (ESO)
TheiconicPillarsofCreationimageofastar-formingregionintheEagleNebula. Credit: NASA, ESA, STScI, J. Hester and P. Scowen (ASU)
National Aeronautics and Space Administration
Orion Nebula, Winter/Spring:Youcancoverthestar-formingregionwithyourthumbatarm’slength.Therearehundredsofstarsbeingbornhere.Dist. 1,300 ly
Lagoon Nebula (M8), Summer/Autumn:Thisnebulaisveryyoungandhasprobablycreatedfewerthan100starssofar.Butitisactiveandcreatingmoreallthetime.Dist. 4,100 ly
STAR NURSERIESEXAMPLES OF STAR NURSERIES
Do you know where stars are born? In a star nursery!
Thishugecloudofgasanddustiscollapsingonitselftocreatenewstars.Manyofthesenewstarswillhaveplanetsaroundthem.OurSunandalloftheplanetsintheSolarSystemalsoformedfromadensecloudofgasanddust,likethisstellarnursery.
Haveyoueverlookedthroughthewindowofahospitalnurseryfullofnewbornbabies?They’reoftenbundledinwarmfleecyblankets.Astarnurseryissimilar.Warmblanketsofgasanddustsurroundthesenewbornstars.
Howlongdoesittakeforstarstoform?AstarlikeourSuntakesabout10millionyearstoform.Ifwecomparethelifeofastartothelifeofahuman,thisstagewouldcorrespondroughlytothetimewespenddevelopinginourmom’sbelliesbeforebirth.
Wheredidthisgasanddustcomefrom?Dyingstarsexplodedandflungtheirremainsintothegalaxy,recyclingthematerialtomakenewstarsandplanets.
Worlds in the womb
Eagle Nebula, Summer:Thenewstarsseenemergingfromthisnurseryareonlyabout5millionyearsold.Theyformedashumanancestorsweredivergingfromtheapes.Thisstarnurseryincludesthefamous“PillarsofCreation”picturebytheHubbleSpaceTelescope.Dist. 7,000 ly
Trifid Nebula, Summer/Autumn::Thenameofthisnebulareferstothedarkgaslanesthatseemtoseparatethebrightareasinto3sections.Dist. 5,000 ly
Vega
Altair
Deneb Kepler Search Area
STARS WITH PLANETS
National Aeronautics and Space Administration
UpsilonAndromedaesystemistwostarsandatleastfourlargeplanets.TheyarenotallinthesameplanelikeourSolarSystembutorbitatvariousangles.
GammaCephei
IotaDraconis
“BigDipper”
“LittleDipper”
Draco
Cepheus
FindGammaCepheibyfollowingalinefromtheBigDipper’spointerstars,throughPolaris,andontothenextbrightstar.IotaDraconisisontheothersideoftheLittleDipperinDracotheDragon.
Andromeda
UpsilonAndromedae
Cassiopeia
Thespace-basedKeplertelescopecontinuouslymonitoredover150,000starsintheSummerTriangle,searchingforexoplanetsinthehabitablezonesofstars.WhileexoplanetsareverydistantcomparedtoplanetsinourSolarSystem,wehaveyettoexploremostofourgalaxy.Milky Way portrait by John Lomberg www.johnlomberg.com
Vega
Altair
Deneb
KeplerSearchArea
“SummerTriangle”
Gamma Cephei, all year (N. Hemisphere):Thisdouble-starsystemwillbecomethenew“NorthStar”inabout1,000years.Thebrighterstarisorbitedbyagasgiantplanet(every2.5years)andasecondsmallreddwarfstar(every60years).Dist: 46 ly
Iota Draconis, all year (N.H.):Thisstar’shugeplanetwasthefirstplanetdiscoveredorbitingagiantstar.Dist: 101 ly
Pollux in Gemini, Winter:Pollux’shugeplanetcausesthestartowobblebackandfortheveryyearandahalf.Detectingthatwobbleishowscientistsfoundtheplanet.Inthesameway,otherstarsinGeminihavealsobeendiscoveredtohaveplanets,butthosestarsaretoodimtoseewithjustoureyes.Dist: 34 ly
Upsilon Andromedae, Autumn:Thiswasthefirstdouble-starsystemdiscoveredtohavemultipleplanets.TheprimarystarofthissystemissimilartoourSun.Butinsteadof8planetsorbiting,ithasanotherstarandatleast4gasgiantplanets,likeJupiter,inorbitaroundit!Theremaybeevenmorewehaven’tdetectedyet.Dist: 44 ly
STARS WITH PLANETSEXAMPLES OF VISIBLE STARS WITH PLANETS
Visions of other worlds inspire wonder: Are we alone?
We’realsofindingrockyplanetsthatmightbetherighttemperatureforliquidwater.Wedon’tknowifthere’slifeonanyotherplanets,butit’sfuntospeculate.
Astechnologyimproves,moreexoplanetsarefound.Currentdatasuggeststhatmoststarsinourgalaxyhaveplanetsorbitingthem.Imaginethepossibilitieswithsomanyworlds!
TheplanetarysystemswearefindingaremuchdifferentthanourSolarSystem.Therearehotgasgiantplanetsthatorbittheirstarsinhours,planetsaroundcoolredstars,andevenrogueplanetswithnostarsatall.
Whilestarswithexoplanetsmaynotberegularobservingtargets,theyin-spirewonderandprovideeasyconversationstartersforthosenewtoastronomy.
Findthelatestnumberofconfirmedexoplanetshere:planetquest.jpl.nasa.gov
SUPERNOVA REMNANTS
WhilelookingforHalley’sCometin1758,CharlesMessiersawtheCrabNebulaandthoughtitmightbeacomet.Afternotingthatitdidnotmoveformanydays,hewasinspiredtocreatealistoffaintfuzzyobjectsthatcouldbemistakenforcomets.Ultimately,helisted110objectsandtheCrabNebulabecameMessier1,orM1.Credit: NASA, ESA, J. Hester, A. Loll (ASU)
VeilNebula
CygnustheSwan
“SummerTriangle”
Ifyoumakeacirclewithyourthumbandindexfingerandholditatarm’slength,theVeilNebula(below)wouldfitinside.Credit: Eric Africa
Lyra
National Aeronautics and Space Administration
Veil Nebula, Summer:Thissupernovaremnantbeganwithagiantstellarexplosionaround5,000-10,000yearsago.Perhapssomeofthefirsthumanssowingcropssawadaytimestarastheywereplanting.Themomentislosttohistoryasitoccurredbeforetherewerewrittenrecords.Dist: 1,470 ly
Crab Nebula (M1), Autumn:Weseetheremainsofamassivestarthatendeditslifeinahugeexplosionalmost1,000yearsago.Chineseastronomersobservedthissupernovaasitbecamevisibleintheyear1054.Itwascalleda“gueststar”becauseitappearedsuddenlyasabrightdotinthesky,visibleeveninthedaytime.Itremainedvisibleatnightforabouttwoyears.Dist: 6,500 ly
EXAMPLES OF SUPERNOVA REMNANTS
We mostly see the brightest stars
SupernovaearethereasonrockyplanetslikeEarthexistatall.Thesehugeexplosionscreatetheheavierelementslikeironandcalcium.Withouttheseelements,trees,rocks,andpeoplecouldnotexist.
Onlytheverylargeststarswillendtheirlivesinasupernova.Sinceweonlyseethebrighteststarsfrommostlocations,manyofthemostcommonstarsweseewillsomedaygosupernova.
Thelastsupernovaobservedinourgalaxywasin1604,butit’sestimatedthatanaverageof3gooffinourgalaxyeveryyear.Betelgeusecouldgoanytime-tonightoramillionyearsfromnow.Itwillprobablybevisibleduringthedayasabrightstarforafewmonthsandeventuallyfadetoaremnantlikethese.
SUPERNOVA REMNANTS
Exoplanet eulogy?
Suchaviolenteventseemslikelytodestroyanyexoplanetsthatwereorbitingthemassivestar.Yet,thefirstdiscoveriesofexoplanetsweremadeforplanet-sizebodiesorbitingpulsars,theneutronstarremnantsofanexplodedsupernova.
Onetypeofsupernovaalwaysemitsastandardamountoflight,sowecandeterminethedistanceoftheexplosion,helpingusansweraveryimportantquestioninastronomy-howfar?