From Planet Detection to Planet Parameters

Michael Perryman

Heidelberg (ZAH/MPIA), currently University of Bristol

Heraeus Conference, 6 June 2011

Monday, June 6, 2011 1 Star accretion Total: 494 planets Planet Detection November 2010 Miscellaneous Colliding Methods planetesimals

Radio Dynamical e!ects Photometry magnetospheresemission

Microlensing Protoplanetary Timing disks Decreasing (ground) Astrometry Imaging planet mass Radial velocity Sub Doppler Re"ected dwarfs Pulsars Radio variability light White Binary Optical dwarfs eclipses masses, Transits Astrometric Photometric 10MJ Δi for multiples survival Space Ground 1 5 12 M J Ground sizes, densities, Slow (adaptive Free atmospheres 81 Bound optics) Space Ground "oating 10M๨ Millisec masses sin i, unbiasedGround/ host star Space × space statistics (coronagraphy/ 22 Timing M๨ 4 resonances interferometry) residuals

Discovered: 10 planets 358 planets 11 planets 12 planets 103 planets

10 planets 461planets 4 planets 11 planets 12 planets 108 planets Detected: (6 systems, (390 systems, (10 systems, (10 systems, (7 systems, 3 multiple) 45 multiple) 1 multiple) 1 multiple) 1 multiple transit)

existing capability projected (10–20 yr) n = planets known discoveries follow-up detections

Monday, June 6, 2011 2 Topics

• radial velocities • astrometry • transits • internal structure and composition • radio emission • population synthesis

Monday, June 6, 2011 3 Monday, June 6, 2011

GJ 581 GJ 876 HD 40307 BD –08 2823 HD 181433 HD 45364 HD 128311 HD 69830 HD 37124 HD 155358 The distribution of multiple systems multiple of distribution The HD 215497 HD 147018 61 Vir

increasing host star mass star host increasing HD 108874 55 Cnc HD 190360 HIP 14810 HD 47186 HD 9446 HD 168443 HD 73526 HD 187123 HD 134987 47 UMa HD 202206 HD 125612 HD 11964 HD 217107 HD 183263 HD 82943 HD 12661 µ Ara HAT–P–13 HD 74156 υ And HD 169830 HD 60532 HD 200964 HD 38529 24 Sex BD +20 2457

0.1 1 10 Semi-major axis, a (AU) 4 Numerous of these multiple systems are in resonance...

For a heuristic physical description, see Peale (1976), ARA&A 14, 215

Many other types of resonance... An object’s mean motion, n ≣ 2π/P • spin-orbit mean motion resonances (P1/P2 ∼ i/j): • tidal locking (1:1) 2:1, 3:1, 4:1, 5:1, 5:2, etc • Mercury (3:2) • Kozai resonance (e versus i) • Lagrange (1:1) resonance • retrograde resonances...

Monday, June 6, 2011 5 Mean motion resonances come in many different flavours, e.g. for the 2:1

(1) unstable 2:1

conjunctions at pericentre (2b) apsidal corotation apsidal alignment (2) stable 2:1 rotates (usually (aligned) conjunctions with libration) at apocentre aligned (symmetric) (3) stable 2:1 (anti-aligned) conjunctions or anti-aligned conjunctions (anti-symmetric) at pericentre aligned (symmetric) both may corotate and/or librate (4) stable 2:1 (2a) apsidal b libration apsidal libration (asymmetric) (small libration asymmetric a angle ⇔ deep apsidal a’ resonance) con!guration

b’ Monday, June 6, 2011 6 ... and the first triple (Laplace) resonance

(a) Galilean satellites of Jupiter PI = 1.769 138 d

Ga PE = 3.551 181 d ny m PG = 7.154 553 d Eu e ro d I p e o a

(a) Galilean satellites of Jupiter PI = 1.769 138 d

Ga PE = 3.551 181 d ny m PG = 7.154 553 d Eu e ro d t = 0 Io p e t = 3P a t = PI t = 2PI I P = 30.4 d (b) GJ 876 planets b, c, e c n(Io) - 3n(Europa) + 2n(Ganymede) = 0 ... to 9 significant digits, Peale (1976), ARA&AP b14, = 61.1 215 d Pe = 126.6 d

t = 0 t = P t = 2P t = 3PI c b I I P = 30.4 d e(b) GJ 876 planetsd b, c, e c 3.48˚ 6.97˚ 10.45˚Pb = 61.1 d Pe = 126.6 d

t = 0 c b t = PC t = 2PC t = 3PC e d 3.48˚ 6.97˚ 10.45˚

t = 0 t = PC t = 2PC t = 3PC

Rivera et al (2010): ApJ 719, 890

Monday, June 6, 2011 7 Question: how do planets get into resonance?

Answer: differential (convergent) migration in the residual gas disk

Sándor et al (2010), A&A 517, A31

Monday, June 6, 2011 8 Topics

• radial velocities • astrometry • transits • internal structure and composition • radio emission • population synthesis

Monday, June 6, 2011 9 Astrometry...

104

150 HR 8799d 1000 1 mas 2012.8 Gl 876

as)

µ ( HD 162020

α 100 HD 41004 100

2011.6 pc 10–200 Jupiter Saturn 10–200 pc Saturn10–200 10

PSR 1620–26 Declination (mas) Declination

50 OGLE-06-109 1 1 µas

Astrometric signature, 0.2 yr 12 yr Earth 20 pc

0.1 OGLE–05–169 2010.4 0 Earth 100 pc OGLE–05–390 0.01 0 50 100 0.001 0.01 0.1 1 10 100 Right ascension (mas) Orbital period (years)

Effect on the star’s motion around But the size of the effect is small... the barycentre

Monday, June 6, 2011 10 ν And observed with the Hubble Space Telescope Fine Guidance Sensors

radial velocity orbit + astrometric displacement = orbit inclination

2.0 4 (a) (b) (c) 2 2004 2

1.5 ν And d (mas) 0 α 1

X residuals (mas) X residuals –2

1.0 4 0 2005 2002

(mas) 2003 y 2006 ν And c 2 –1 0.5 0

Astrometric signature, signature, Astrometric ν And ν And b –2 Y residuals (mas) Y residuals –2 0.0 0 8 16 24 32 40 400 800 1200 1600 –2 –1 0 1 2 Inclination (˚) JD – 2 452 000 (d) x (mas)

gives a (large) mutual inclination between planet orbits of Δcd = 29.9 deg McArthur et al (2010): ApJ 715, 1203

Important for determining statistics of co-planarity, as inputs to theories of formation and dynamical stability (in future: Gaia, PRIMA)

Monday, June 6, 2011 11 Planet mandalas... .. and the nature of the solar dynamo

(a) Sun 4 planets, 60 yr (b) µ Ara 4 planets, 30 yr (c) HD 37124 3 planets, 30 yr

2020

2010 1970 1990 2030

1980 2000

–0.008 –0.004 0 0.004 0.008 –0.01 0 0.01 –0.002 0 0.002 0.004 Displacement (AU) Displacement (AU) Displacement (AU)

... exoplanets may allow verification whether angular momentum changes are responsible for some of the solar activity modulations (Perryman & Schulze-Hartung (2011): A&A 525, 65)

Monday, June 6, 2011 12 Topics

• radial velocities • astrometry • transits • internal structure and composition • radio emission • population synthesis

Monday, June 6, 2011 13 Transits

1 2 3 4

!ux b R* = a cos i !ux = star + planet

secondary eclipse

ux Increasing ! tT time ΔF transit

tF

The transiting systems have proven of great importance: for densities from absolute masses + accurate radii atmospheric probes from transits and secondary eclipses

Monday, June 6, 2011 14 Transit photometry: example state-of-the-art

WASP–17 b

0.0 ux

! 1.00 –0.01 0.99 erential magnitude erential !

Di 0.98

–0.02 Relative

u’ (326-386 nm) CoRoT−1 1.0002

0.0 ux

! 1.0001

–0.01 erential magnitude erential !

Di 1.0000 Relative Relative –0.02 g’ (413-551 nm) 0.9999

0.0 0.0 0.2 0.4 0.6 0.8 1.0 Orbital phase –0.01 erential magnitude erential ! Di transit transit

–0.02 eclipse

r’ (557-695 nm)

–0.06 –0.04 –0.02 0.0 0.02 0.04 0.06 Orbital phase ...from space, using CoRoT ...from the ground, using ULTRACAM Snellen et al (2009), Nature 459, 543 Bento et al 2011, in preparation

Monday, June 6, 2011 15 Principle of transmission & emission spectroscopy

Transit: Secondary eclipse: transmission = A−B emission = C−D

A B C D

star light star light absorbed by re"ected/re-emitted atmosphere by atmosphere

area of planetary atmosphere intercepted: annulus of width ∼5H, where Many results (e.g. Spitzer) from, notably HD 209458 and HD 189733: H, H2O, CO2, CH4, Na, etc

Monday, June 6, 2011 16 Other transit examples...

) WASP–1 2.520 d WASP–2 2.152 d XO–1 3.942 d ๬

R 1 (

ღ 0 R 1.00 0.98 Flux HAT–P–1 4.465 d HAT–P–2 5.633 d HAT–P–3 2.900 d )

๬ 1 R

( 0 ღ R 1.00 0.98 Flux

) HAT–P–5 2.788 d HAT–P–6 3.853 d GJ 436 2.644 d ๬

R 1 (

ღ 0 R 1.00

Flux 0.98 –4 –2 0 2 4 –4 –2 0 2 4 –4 –2 0 2 4 Hours Hours Hours Torres et al (2008) ApJ 677, 1324

Monday, June 6, 2011 17 Higher-order effects

• from transit light-curve: • stellar density, ρ∗ • planet surface gravity, gp=GMp/Rp • planet limb darkening • higher-order photometric effects: • planet: satellites, rings/comets, planet oblateness, rotation, weather, bow shocks • star: spots, effects of rapid rotation, ellipsoidal variations • higher-order spectroscopic effects: • projected angle between stellar spin axis and planet orbit (Rossiter-McLaughlin) • effects of atmospheric opacity, atmospheric winds • higher-order timing effects: • apsidal precession due to tidal bulges, rotational flattening, general relativity • nodal precession in the case of polar orbits (WASP-33) • effects of planet satellites • effects of other planets, including Trojans • perspective effects due to star’s parallax and proper motion • magnetic breaking, non-gravitational forces (Yarkovsky effect)

Monday, June 6, 2011 18 Rossiter-McLaughlin effect

Winn et al (2006), ApJ 653, L69

1.01 HD 189733 1.00

ux 0.99 ! 0.98

0.97 Relative Relative C – O

b = – 0.5, λ = 0" b = – 0.5, λ = 30" b = – 0.5, λ = 60" –0.04 –0.02 0.0 0.02 0.04 ) 1

− Time since mid-transit (d) + 60 +200

0 ) 1 +100 −

– 60 0

Rad (m s velocity –2 –1 0 1 2 –2 –1 0 1 2 –2 –1 0 1 2 #100 Time (h) Time (h) Time (h) #200 Radial (m s velocity O – C –1.0 –0.5 0.0 0.5 1.0 Time since mid-transit (d)

+100

) + 50

some orbits are retrograde 1 − statistics suggest scattering: Triaud et al (2010), A&A 524, 25 0 or scattering + migration: Marchi et al (2009), MNRAS 394, L93 # 50 but not migration alone O – C

Monday, June 6, 2011 Radial (m s velocity 19

–0.10 –0.05 0.0 0.05 0.10 Time since mid-transit (d) Other transiting phenomena observed...

Kepler−9b individual transits Porb = 19.2 d with variations of 1.000 ~4 min per orbit 1.00 0.995 Flux 0.99 Flux star spots

0.98 1.000 transits shifted HD 189733 to common centre 7 mmag 0.001 0.995 residuals 0 ~4.5 hr –0.001 –0.04 –0.02 0 0.02 0.04 Orbital phase Kepler−9c individual transits Porb = 38.9 d with variations of star spots: Pont et al (2007) 1.000 ~39 min per orbit

0.995 Flux

Orbital phase 1.000 0.96 0.98 1.00 1.02 1.04 transits shifted ("!!! to common centre ux ! !"##' ELC model !t 0.995 !"##& !"##% (a) HAT−P−7

Normalised −0.2 −0.1 0.0 0.1 0.2 !"##$ Time (d) ux ! ("!!!( transit time variations due to

("!!!! resonant planets: Holman et al (2010) (b) Normalised 0.10 0.30 0.50 0.70 0.90 Orbital phase ellipsoidal effects: Welsh et al (2010) • Kepler-11 has 6 transiting planets, with periods of 10, 13, 22, 32,47, and 118 days

Monday, June 6, 2011 20 .. and which may be observable...

epoch 1 epoch 2 proper motion

HD 189733

R* = 370 d∗ θ 181

A’ A Rp = 120 95 64 B

Earth orbit

E1S1 W1E1 S1W1 perspective effects 0.008 (Rafikov 2009, Scharf 2007) 0.000 Visibility –0.008 0.2 1.04 0.1 0.0 1.02 –0.1 ux Closure phase (˚) Closure

! –0.2 1.00 0.04 0.08 0.12 0.04 0.08 0.12 Time (d) Time (d)

Relative Relative 0.98

0.96 Transit geometry from 2d interferometry 0 1 2 3 4 5 (van Belle 2008: PASP, 120, 617) Time (d) close-in, spun-up systems (Pont 2009: MNRAS 396, 1789)

Monday, June 6, 2011 21 These transiting systems are extreme laboratories:

2 ρ = 0.25 ρJ TrES–4 WASP–12 ρ = ρJ ρ = 10 ρ WASP–17 J OGLE–TR–10 OGLE–TR–L9 WASP–12 J 1.5

R Kepler–7 /

p HD 209458 R HD 189733 WASP–14 XO–3 HAT–P–19 HAT–P–18 CoRoT–3 1 HAT–P–12 J S HAT–P–26 HAT–P–20 Planet radius, radius, Planet SWEEPS–04 GJ 436 HD 149026 0.5 GJ 1214 CoRoT–8 U HAT–P–11 N Kepler–4 E CoRoT–7 V 0 0.001 0.01 0.1 1 10 100 Planet mass, Mp/MJ densities are as low as 0.09 Mg m-3 (WASP-17) shortest orbital periods of 0.79 day (WASP-19) the stellar disk subtends up to 35 degrees (WASP-12) longest orbital period (with e = 0.93) is 111 day (HD 80606) some orbits are highly misaligned or retrograde extreme tidal bulges, up to 70 km high relativistic apsidal and nodal precession (WASP-33)

Monday, June 6, 2011 22 Topics

• radial velocities • astrometry • transits • internal structure and composition • radio emission • population synthesis

Monday, June 6, 2011 23 Chemical composition and condensation

Several areas of exoplanet research require estimates of composition versus temperature and pressure (agglomeration during formation, modeling interiors and bulk properties, formation of atmospheres, etc)

Steps (see, e.g., Lodders 2003, ApJ 591, 1220): 1. start with a certain initial elemental composition (e.g. assumed solar nebula composition) 2. assume time for the relevant chemical reactions to reach equilibrium at given T and P 3. use thermodynamic equilibrium calculations to predict gas/gas-grain/solid phase reactions 4. predict which gases form, which elements or compounds condense, and in which proportions

terrestrial gas giants ice giants rock-ice

300 1.0 ) 15 ๨ 0.002 M 200 10 phase ( 0.5 classification of solar system bodies of

0.001 100 5 into four compositional types: Mass terrestrial, gas giants, ice giants, and 0 0 0 0 dwarf planets M V E M J S U N P rocky rocky + icy rocky + icy rocky + icy (Lodders 2010, Exoplanet Chemistry) (metallic + silicates) + H2/He >50% + H2/He <50%

metallic silicate ice H/He

Monday, June 6, 2011 24 Effect of gravity on shape and structure versus mass

1030 Sun 80 MJ → hydrogen fusion

1028 13 MJ → deuterium fusion degeneracy pressure Jupiter ~ Coulomb pressure 26 10 Uranus

Earth 1024 Mars convection important Object mass (kg) Moon compression important 1022 chemistry modi!ed Ceres gravity ⇒ sphericity 1020 Pallas Miranda

Hyperion 1018

1016

1014 Comet Tempel 1 gravity ⇒ cohesion 0 2 4 6 Density (Mg m–3) Physical process Monday, June 6, 2011 25 Mass versus radius (a powerful diagnostic of interiors)

4 0 6 e 1 Gyr (Z ) ic ȧ O 2 H 10 Gyr rm −0.2 a 5 3 w re u brown dwarfs Uranus p Radius, km)

4 Neptune ck 4 ro ) −0.4 planets stars re u ȧ

(10 p R R ( R/R

2 R

3 ๨ ) −0.6 log ( Radius, ron re i R ∝ M Moon Mercury pu 2 1 Mars Titan −0.8 CoRoT−3b n = 1 1 0 Earth R ∝ M Venus −1.0 0 0 0.01 0.1 1 10 100 1000 (a) M = 5M๨ mantle (b) M = 5M๨ mantle n = 1.5 (c) M = 1M๨ mantle Jupiter HAT−P−2b R ∝ M−1/3 Mass (M๨) 100 0 100 0 100 0 −1.2 −3 −2 −1 0 Fortney et al (2007), ApJ 659, 1661 Earth 80 20 (no 80 log (M/M20ȧ) 80 20 B terrestrial sidewater) 10750 km C 60 9800 km 40 Chabrier60 et al40 (2009), 60 40 maximum A radius 12200 km AIP Conf 1094, 102 40 D 60 40 60 40 60 10950 km minimum radius 12650 12000 11350 10650 10000 9350

8650 8000 6650 xed Si/Fe ratio 20 20 7350 20 ! 80 80 6000 80 late delivery of H

2O 100 100 100 H 0 H 0 H 0 2 O 2 O 2 O 100 80 60 40 20 0 core 100 80 60 40 20 0 core 100 80 60 40 20 0 core ternary diagrams (Valencia et al 2007, ApJ 665, 1413)

Monday, June 6, 2011 26 Interiors and atmospheres: hydrogen

105 + H θ = 0.1 θ = 0.03

104 H atomic (K) T H+ metallic Guillot (2005), AREPS, 33, 493 HD 209458b

103 Jupiter

Temperature, Temperature, Saturn Uranus, Neptune Ι 102 H2 molecular ΙΙΙ solid H gas 2 ΙΙ

H2 liquid 101 105 107 109 1011 1013 Pressure, P (Pa) Notes: * molecular-metallic transition * solidification possible at low T and high P, but relevant for an isolated Jupiter only after ∼1000 Gyr of cooling (Hubbard 1968) * P−T profiles for solar system giants and HD 209458 Monday, June 6, 2011 27 Interiors and atmospheres: water (1/2)

Tcrit 1012 X XI Phase diagram VIII VII supercritical for water XV VI critical 9 10 point !uid (Chaplin 2010) V liquid critical isochor IX II III Pcrit V (Pa)

P gas 106 Ic Ih E

Pressure, Pressure, XI

103 M vapour

solid triple point

1

0 100 200 300 400 500 600 700 800 900 1000 Temperature, T (K)

19 solid phases: ice XII discovered in 1996, XIII-XIV in 2006, and XV in 2009 16 crystalline polymorphs: hexagonal, cubic, monoclinic, orthorhombic, tetragonal... densities are <1 for Ih/Ic only, and reach 2.5 for ice X ice VII (and perhaps X/XI) are most relevant for planetary interiors (Valencia et al 2007)

[properties collated by the International Association for the Properties of Water and Steam]

Monday, June 6, 2011 28 Interiors and atmospheres: water (2/2)

1.0 (+ IV, XII, XIII, XIV) solid 0.8 1.20 VI (Mg m Density 0.6 V 1.15 adiabat 0.4 II

isotherm 1.10 Pressure (GPa) Pressure III 0.2 –3 ) solid Ih 1.05 liquid 0 1.00 –60 –40 –20 0 +20 Temperature (C)

For a 6MEarth ‘ocean planet’ in the habitable zone with Tsurface = 7C, Leger et al (2004, Icarus 169, 499) derived: ocean depth = 45−72 km (isothermal-adiabatic)

Monday, June 6, 2011 29 Topics

• radial velocities • astrometry • transits • internal structure and composition • radio emission • population synthesis

Monday, June 6, 2011 30 Radio emission

sts ur I b di 8 type II stu 10 Solar rbe d Sun s ky ba rotation axis Jupiter ckgr magnetosphere (bursts) ound 106 Earth at 1 AU Jupiter un t S uie solar wind q n o ! o 4 Cas M 10 C A yg A Saturn Crab magnetic !eld lines Uranus 3C 29 Vi magnetic 2 5 r A 10 3C 2 ionospheric cut-o 73 dipole axis density (Jy)Flux on Neptune ri magnetopause O Jupiter Jupiter UTR-2 s 1 (bursts × 105 ar M at 10 pc) Five of the solar system planets with Boo

Jupiter τ dynamo-driven magnetic fields Vir 70 –2 3 10 (bursts × 10 LOFAR (1 s, 4 MHz) produce low frequency at 10 pc) 70 Vir (cyclotron) emission. Boo τ LOFAR (1 hr, 4 MHz) So far, no exoplanets.... 10–4 0.1 1 10 100 1000 10000 Frequency (MHz)

Monday, June 6, 2011 31 Topics

• radial velocities • astrometry • transits • internal structure and composition • radio emission • population synthesis

Monday, June 6, 2011 32 Planet formation: growth by 14 orders of magnitude (in one viewgraph)

Time scale 103 ? 103 −106 ?? 103 −104 105 107 −108 (year)

proto- terrestrial gas dust rocks planetesimals Body planets planets giants

pairwise collisional post- Inner particle agglomeration mechanism growth or runaway oligarchic oligarchic disk (settling and radial migration) particularly uncertain Goldreich-Ward growth growth (chaotic) fragmentation growth

Outer disk core accretion or gravitational instability

–6 10–4 10–2 100 10+2 10+4 10+6 10+8 10 Diameter (m) 1 km 10 km 100 km 1000 km 10 000 km 100 000 km

Monday, June 6, 2011 33 Population synthesis

104 104 (a) (b)

feeding 103

limit ) ๨ M

( 2 p 10 103 outer M group

main 10

) clump ๨ M

( 1

p 0.1 1 10 M 102 a (AU) (c) M 6 102 Menv 5

horizontal ) ๨ M z 4 a

branch (AU) M 10

10 ( p

M 3

1 2 failed cores a 1 1 0.1 1 10 3 4 5 6 Semi-major axis, a (AU) Time (Myr)

there are enough planets that a statistical approach to model results is now possible e.g. Mordasini et al (2009): A&A 501, 1139

Monday, June 6, 2011 34 Just published - topics covered:

1. Introduction 2. Radial velocities 3. Astrometry 4. Timing 5. Microlensing 6. Transits 7. Imaging 8. Host stars 9. Brown dwarfs 10. Formation and evolution 11. Interiors and atmospheres 12. The solar system

Monday, June 6, 2011 35 The End

Monday, June 6, 2011 36