Planet

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Planet

Garik IsraelianInstitute of Astrophysics of Canary Islands, SpainEuropean Northern Observatory


La Palma Observatory (ORM)2590 meter a.s.l.TeideTeideObservatoryObservatory25902590metermetera.s.l.a.s.l.


La Palma


La PalmaGTC: 10.4 meterThe largest telescope in the world


La PalmaGalileo: 3.5 meterItalian National Telescope


La PalmaMAGIC cosmic ray telescopeThe most precise telescope in the world


La PalmaMERCATOR Swiss-Belgian1.2 meter robotic telescope


La PalmaWHT: 4.2 meterThe most reliable and productivetelescope in the world


La PalmaORM Observatory2600 meter a.b.s


La PalmaORM Observatory2600 meter a.b.s


La PalmaGTC: 10.4 meterThe largest telescope in the world


TenerifeTeide Observatory2590 meter a.s.l.


TenerifeTeide Observatory2590 meter a.s.l.


Some planets were known to the ancients whowatched them move against the night sky.Courtesy NASA’s Navigator Program2


Mercury, Venus, Mars, Jupiter, andSaturn were the “Wandering Stars.”Courtesy NASA’s Navigator Program“Planet” comes from the Greek word for “wanderer.”


And other planets were “discovered.”UranusThe year 1781The first planet “discovered.”William and Caroline HerschelNeptuneThe year 1846First observed by Galle and d'Arrest(based on calculations by Adamsand Le Verrier).PlutoThe year 1930Discovered by Clyde TombaughCourtesy NASA’s Navigator Program5


But what about more distant worlds? Thousandsof years ago, Greek philosophers speculated.“There are infiniteworlds both like andunlike this world ofours...We mustbelieve that in allworlds there are livingcreatures and planetsand other things wesee in this world.”Epicuriusc. 300 B.CCourtesy NASA’s Navigator Program


And so did medievalscholars. The year 1584"There are countless suns andcountless earths all rotatingaround their suns in exactlythe same way as the sevenplanets of our system . . .The countless worlds in theuniverse are no worse andno less inhabited than ourEarth”Giordano Brunoin De L'infinitoUniverso E MondiCourtesy NASA’s Navigator Program4


In 1995, a breakthrough:the first planet around another star.Michel Mayor and Didier QuelozA Swiss team discovers a planet – 51 Pegasi –48 light years from Earth.Courtesy NASA’s Navigator Program 7Artist's concept of an extrasolar planet (Greg Bacon, STScI)


Methods to Detect PlanetsSpitzer, for the first time,captured the light from twoknown planets orbiting starsother than our Sun. But so far,most of the extra-solarplanets are being detectedusing INDIRECT methods.Artist Concept:NASA’s Spitzer Infrared Telescope


Methods to Detect PlanetsThere are several complementary methodsfor detecting planets orbiting distant stars.WobbleDoppler – detecting the star wobbling in the line of sightdue to the planet’s gravitational pullAstrometry – detecting tiny wobble of stars againstother stars in the background.Planet Transit – detecting a tiny drop in brightness ofthe star as a planet passes in frontCoronograph – blotting out the light of the star soplanets can be “seen”TransitCoronographAstrometry


Massive Planets Cause Stars to Wobble• Stars and their planets also moveabout the common center of mass.• Since the mass of a star is so muchgreater than the mass of a planet,the “center of mass” (i.e. “balancepoint”) is located close to (but not atthe center) of the parent star.• This means that stars with planetsin orbit around them are notstationary. Rather, they move slightlyabout this balance point producing agravitational wobble!• The gravitational wobble of the Sunis dominated by the gravity of themost massive planet Jupiter.Star moving toward observer(positive velocity)far sideof orbitStar moving awaynear sideof orbit


NASA’s SIM PlanetQuest MissionAre there terrestrial planets orbiting nearby stars?NASA’s SIM PlanetQuestMission will survey nearbystars for Earth-size planets bymeasuring the wobble of starsagainst other stars in thebackground.Artist Conception: NASA’s SIM PlanetQuestThis method of detection iscalled astrometry.


Doppler shift to measure the tug of planets onstars. Here is how it works:So far, nearly all extrasolarplanets have beendiscovered with thistechniqueIf an unseenplanet tugs thestar back andforth……the light fromthe star shiftsslightly to thered as the starmoves away fromyou.…and slightly tothe blue as itmoves towardyou.Astronomers candetect these shiftsby very carefullyobserving thespectra (or colors) ofthe stars.Courtesy NASA’s Navigator Program


Detecting Planets: Transit MethodKeplerNASA’s Keplermission will usethe transit method.When a planet passes by (or transits) astar, we can detect a slight decrease inthe amount of light from the star.


: - (‏‏)‏ • – – : ^ – : - (‏‏)‏ • COROT– – : ^– : - Kepler


Coronograph: We will block out the bright lightfrom the star.Telescopes that block thelight from the central starcan take images of planetsthat might be in orbitaround them.Keck InterferometerThe Keck Interferometercombines the light of two10-meter telescopes to takeimages of hot Jupiter-sizeplanets that shine bright ininfrared light.


T eff = 5800 K 24000 lines in the optical spectrum of the Sun. 15 % not yet identified !T eff = 9900 K


How precise ?accuracy


First planets and first “problems”(‏‎1995‎‏)‏ Mayor & QuelozStrange world:msin(i)=0.47M JupP=4.2 daysSeparation=0.05 AU


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! ! !!! Need to revise theories Look at the statistical properties


Mass distribution (HARPS)


Benz et al. (2009)


M > 0.75 MjupM < 0.75 MjupNeptunes:- ( . (‏ .


-No planetswith shortP and highMass!


EccentricityDistribution!Only smalldifferencebetweenbinary starsand planets!


EccentricityDistribution!Mayor et al2012


... - -


Planet frequency and stellar [Fe/H](‏‎2001-2005‎‏)‏ Santos, Israelian & Mayor


Is the sametrue forNeptunes?Sousa et al2011


Is the sametrue forNeptunes?Mayor et al20l2


Is the sametrue forEarths?Buchhave et al. 2012


Chemical CompositionPrimordialSecondaryPlanet formation and stellarevolution does not modifystellar surface abundancepollutionGrav. settling, etc


Giant Planet(Jupiter)10M ⊕.10 core(Fe, Ni, Si, Ti..)HHe€SunPlanet(s)accretionSun


Fractionation ?SunhotcoldRefractories: Fe, Mg, Si...Volatiles: C, N, O, S & ZnSunTerrestrial Planets: Fe, MgSi, Ca etc. chondritic matterGiant Planets: icy cores,CO 2 H 2 O NH 4 etc.


Smith et al. (2000)Not confirmed bySadakane et al. (2002),Takeda et al. (2001)T c (K)Condensation temperatureCondensation temperature


Graphite, TiC ysolid Si as SiCPyroxeneMgSiO3OlivineMg2SiO4Mg/Si abundance ratios are larger in planet-host stars than in stars withoutknown planets, although part of this signature is probably due to chemicalevolution effects since planet-host stars are on average more metal-rich thansingle stars.


Light elements Li and BeAngular momentum exchange:Momentum locked in planetsTransfered to the star by accreted objectsTidal effectsMS accretion of planetesimals, ingulfment ofplanets-testFlare activity (spallation reactions: Li & Be))


T > 2.5 ×10 6 K ⇒ 7 Li is destroyedT < 2.5 ×10 6 K ⇒ 7 Li is preservedT > 3.0 ×10 6 K ⇒ Be is destroyedT < 3.0 ×10 6 K ⇒ Be is preserved €T > 2.0 ×10 6 K ⇒ 6 Li is destroyedT < 2.0 ×10 6 K ⇒ 6 Li is preservedT > 3.5 ×10 6 K ⇒ B is destroyedT < 3.5 ×10 6 K ⇒ B is preservedConvective cellsLi€€T > 2.5 ×10 6 K


M67 open cluster●Pasquini et al. 2008


It is possible, in principle anyway, that the low Li abundances ofthe Sun and 16 Cyg B with respect to 16 Cyg A may be relatedto the presence of planetary companion. Li abundances of 47UMa, and HD114762 might further support such a connectionbetween planets/disks, angular momentum evolution, andphotospheric Li abundance.King et al. (AJ, 113, 1871, 1997)16 Cyg B 16 Cyg ALog LiLog Li


YES or NOGonzalez & Laws (2000)Ryan (2000)Israelian et al. (2004)Takeda & Kawanomoto (2005)Chen & Zhao (2006)Luck & Heiter (2006)Takeda et al. (2007)Gonzalez (2008)yesnoyesyesyesnoyesyes


YES or NOIsraelian et al. (2009)Gonzalez (2010)Takeda et al. (2010)Baumann et al (2010)Ghezzi et al. (2010)Sousa et al. (2010)Delgado Mena et al. (2011)yesyesyesnonoyesyes


Li abundances for 23 planet-host stars and 60 stars without planetsfrom HARPS GTO program and CORALIE program


Young population (1-3 Gyr)?Old population (6-8 Gyr) ?Age effect/bias ?


Planet HARPS Single starssingle stars HARPS -M


T eff =6000 K[Fe/H]=0Fully convectiveT > 2 10 6 KIngestion of planets &Accretion of planetesimalsT bottom < 2 10 6 KPMSMSMSLog Li=3.36Li / 7 Li=0.08AGE=1 MyrLog Li=2.56Li / 7 Li=0.0AGE=30 MyrLog Li > 2.56Li / 7 Li > 0.0AGE > 50 Myr


EW( 6 Li ) ~ 5 mA0.001T eff =6200 K.6Li / 7 Li=0.066Log Li=2.5Murray & Chaboyer (2002)Log Li=3.2


HD 82943 Israelian et al. (Nature, 2001)FeICN0.060.00


HD 91889HD 82943Normalized FluxFeICNWavelengthWavelengthThe Li6-test (Israelian et al. Nature, 411, 163, 2001)


Planetary migrationd > 5 AUPlanetary migration:dynamical frictiond > 5 AUTime-scale ~ 10-20 MyrDense gas/dust accretion diskdrag effect, torque etcTime-scale: up to 1 GyrplanetesimalsNO gas0.0001M sun < M disk < 0.1M sun


Multi-body interactions:no gas/dust, no planetesimalsMulti-body interactions &planetesimals diskTime-scale: up to 100 MyrFew large planets, orbital radii evolveat different rates.Time-scale: up to 1 Gyr or moreNo accretion disk, dust & gasonly planetesimals?


Tectonic & Volcanic activityIs there enough Th, U and K ?


HD115585Sun like star with a planetary systemThorium40 % more Thorium !


Sun & HD65216VLT UVESOsmium


Red edgeCloud free vegetated area


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Thank You!

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