OBSERVING CARDS - NASA

OBSERVING CARDSINDEX

National Aeronautics and Space Administration

Index

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


Index

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

nightsky.jpl.nasa.gov


Index

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


Index

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

Index

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


astropics.com

Index

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!

Index

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


Index

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.

Index

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


Index

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.

Index

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.


Index

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

Index

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)


Index

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.

Index

PLANETSVenusisclosertotheSunthanweare,givingusdifferentviewsofthehalf-litsphereovertime.

Saturn’sringsareprobablypiecesofcrushedasteroidsandcomets,rangingfromsugar-tohouse-sized.

Comparesizes(notdistances)oftheSunandplanetsinourSolarSystem.

ThevisiblefeaturesonJupiteraremostlyammoniaclouds.

RoversonMarsgivegreatviews,butonlyseeasmallportionoftheplanet.ImaginetryingtolearnallaboutEarthfromagolfcart.


Index

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.

Index

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


Index

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

Index

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)


Index

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

Index

Vega

Altair

Deneb Kepler Search Area

STARS WITH PLANETS


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”

www.johnlomberg.com

Index

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


Index

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


Index

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?

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