From Planet Detection to Planet Parameters
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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 distribution of 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 Saturn 10–200 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..