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Observed Properties of Multiple - Planet Systems Properties of Multi-Planet Systems: Outline of Talk Properties of Single Planets (Review of Last Time) Theory: Migration & Planets Tug on Planets Neptune-Mass Planets: First Observations Multi-Planet Systems: Properties Mean-Motion Resonances Formation & Evolution Puzzles Exoplanet Detection Methods Proven Techniques # Planetary Systems Precise Doppler: Transits: Gravitational lensing: Direct Imaging: Techniques for the Future Astrometry: Precise Doppler Kepler 170 8 3? 2? Review Last Time NASA/JPL 178 Giant Exoplanets Detected Around Sun-Like Stars Doppler Detection of Wobble of Star orbiting common center of mass with planet(s). Stars Wobble: Gravitational pull of Planets Spectrum of starlight QuickTime™ and a Sorenson Video 3 decompressor are needed to see this picture. Doppler Effect of Star Light Starlight From Telescope High Resolution ``Echelle” Spectrometer Echelle Spectrometer CCD Echelle Grating Collimator Spectrum of Star: Doppler Effect Saturn induces 3 m/s in Sun : 0.001 pixel Doppler Precision: 1 m/s v / c ~ 3 x 10-9 Dl / l ~ 3 x 10-9 4096 Pixels 1300 FGKM Nearby Stars Doppler Precision: 3 m s-1 115 Extrasolar Planets Three Telescopes 19 Yrs (6 AU) Lick 8 Yrs (4 AU) Keck 7 Yrs (3.5 AU) Anglo-Aus. Tel. Doppler Precision: 1.0 ms-1 Keck HIRES Upgrade (2004) 1 year Known Exoplanets Jan 1996 178 a = 0 - 5 AU M sini = 0.05-15 MJUP Multiple Planets Nearly half found by: Swiss team Harvard teams Texas teams New Planet 2.96 MJUP P = 5.3 yr e = 0.47 New Planet: P = 1.3 yr e ~ 0.1 Sub-Saturn Masses: 30 - 100 MEarth Msini = 32 MEarth Msini = 37 MEarth Msini = 57 MEarth Sub-Saturn Masses: QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Detectable for P < 3 Month Review Giant Planets: Mass Distribution Detection Limit: ~ 0.2 MJUP @ 1 AU Rise toward low masses to 1 MSAT Sub-Saturn? Semimajor Axis Distribution Poor Detectability Rise 6.5 % Occurrence Flat Extrapolation: D6% of stars have planets 3 - 20 AU . Total: 12 % Prediction: Reservoir of Jupiters at 5-20 AU Log Models: Inward Migration. Planets left in place as disk vanishes . Future: Gas Giants Orbiting Beyond 5 AU G0 V Represents 5 % of Stars Orbits: Circular or Eccentric? Orbital Eccentricities Tidal Circ.: a < 0.07 AU <e>=0.25 <e> = 0.25 Origin of eccent. controversial . (But suggestion later, and talk by Veras & Armitage) Ecc still high Beyond 2.5 AU Super-Earths: 1 - 14 MEarth The Next Domain Earth - Uranus: Gap in Mass: Factor 14 Terrestrial SuperEarths ? Intermediate Masses: Do they Form? Or do planet embryos accrete gas ala Neptune ? Ice & Gas giants If They Form: - Terr-like: CO2 Atm. ? - Neptune-like H&He env ? Density: 1 or 5 g cm-3 ? and life in the universe Next Frontier: First Search for Habitable Worlds Too hot Temp = 0 - 100 C Will Need an Extraordinary, New Telescope To Detect Earth-Like Planets. NASA . . . Too cold NASA’s Effort to: Discover Earths Orbiting other Stars QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Kepler: SIM: First Survey for Earths: Occurrence rate. d = 1 kpc, No masses Finds Nearby (d< 20 pc) Earths: Measures masses and orbits. Follow-up: IR disks, Doppler, Imaging planets (TPF, AO) Observed Properties of Multiple - Planet Systems HD 12661 (G0 V) Periodogram P = 5yr QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. HD 12661: 2 - Planet Model RMS=3.4 m/s 2.5 MJ 1.9 MJ Possible 6:1 Resonance Weak Interactions Gozdziewski & Maciejewski, Lee & Peale K0V, 1Gy, 16 pc HD 128311 2:1 Resonance Inner Outer Per (d) 458 918 Msini 2.3 3.1 ecc 0.23 0.22 w 119 212 Pc / Pb = 2.004 Dynamical Resonance (Laughlin) Upsilon Andromedae First multiple-planet system discovered around a regular “main sequence” star in 1999. SFSU Now have ~ 450 Doppler observations with precision limited by stellar jitter of ~ 7.5m/s Upsilon And c & d have significant orbital eccentricities (e = 0.25 & 0.27 ±0.02) Orbit Eccentricities change during 1000 years. What is the origin of these eccentricities? Mass = 0.62 MJUP 60 Days 0.65 0.70 0.75 0.80 Upsilon Andromedae: Velocity Residuals D omega = 48 deg Circulating Or Librating? eC P Tp ecc w K Msini a (d) (JD-2450000) (deg) (m/s) (MJUP) (AU) ----------------------------------------------------------------------------4.61712 2.01588 0.028 66.7 68.1 0.66 0.059 241.2 160.4765 0.24 252 55.7 1.97 0.828 1318.4 138.3883 0.28 300 62.2 3.84 2.569 0 ? . Upsilon Andromedae: . Triple Planet System e=0.27 . 2 MJUP QuickTime™ and a TIFF (Uncomp resse d) de com press or are nee ded to s ee this picture. . 0.6 MJUP e=0.25 0? . . Impulsive Origin of ecc ? (Ford, Rasio, Malhotra) 4 MJup . . . . Planet-Planet Scattering: Impulsive Origin Of Eccentricites ? Upsilon Andromeda: Origin of Eccentricities Initial Eccentricity = 0 QuickTime™ and a Sorenson Video 3 decompressor are needed to see this picture. Gliese 876 Real-Time Mean-Motion Resonance and first Super Earth: Star’s Mass = 0.32 Msun Two Jupiters in 2:1 res. GJ 876: Velocities Two-Planet Model Resid Time Laughlin et al. 2004 GL 876 2:1 Mean-Motion Resonance & Apsidal Lock Inner Outer P 30.1 61.0 d Msini 0.56 1.89 MJ e 0.27 0.10 w 330 333 o Resonance Work: Laughlin & Chambers Lissauer & Rivera Man Hoi Lee & S.Peale Gliese 876 2:1 Mean Motion Resonance Precession Period: 9 yr Man Hoi Lee Marcy stopped here, as time ran out. GJ 876: Velocities Two-Planet Model Laughlin et al. 2004 Velocity Residuals to 2-Planet fit Period = 1.94 d Velocity M sini = 5.9 MEarth For i = 50 deg, MPL = 7.5 MEarth Orbital Phase Lowest Mass Exoplanet to date. 3-Planet Fit Rivera & Lissauer Gliese 876 Two Jupiters in 2:1 Resonance 7 1/2 Earth-Mass Planet 7 1/2 Earth-masses Excitation of Eccentricity Tidal Heating 178 a, MPL, ecc shown 20 multi-planet systems 151 planet-bearing stars 5 Mean-Motion Resonances: Gl 876 (2:1) 55 Cnc (3:1) HD 82943 (2:1) HD 73526 (2:1) HD 128311 (2:1) Proposed M-M Res. : HD 37124 (5:1 ?) HD 12661 (6:1 ?) HD 202206 (6:1 ?) Compare Multi-Planet systems to singleplanet systems Single-Planet Systems Planet Mass Distributions M sini (MJUP) Ups And Multi-Planet Systems QuickTime™ and a Graphics decompressor are needed to see this picture. Neptunes Saturn Common Paucity Explanation? M sini (MJUP) Single-Planets Eccentricities: No Sig. Difference; GJ 876 Multi-Planets Surprising: Multi-systems should suffer resonances & perturbations Summary Planet Mass Distribution: Peaks Below 1 MSAT Semimajor Axis Distrib. Rises toward 5 AU Multi-planet Systems common Mean-Motion Resonances Common Migration, capture, eccentricity pumping Properties of Multi-Planets not very different from single-planet systems: Common processes? Total eccentricity vs Total Planet Mass QuickTime™ and a Graphics decompressor are needed to see this picture. GJ 876 More mass Higher eccentricity Planet Mass Ratio QuickTime™ and a Graphics decompressor are needed to see this picture. GJ 876 Period Ratio Stability of large Mass ratios Requires wide separation 13 7 GJ 876 Outer planet tends to be more massive. QuickTime™ and a Graphics decompressor are needed to see this picture. GJ 876 Single-Planets Metalicity Dependence QuickTime™ and a Graphics decompressor are needed to see this picture. GJ 876 Same for Single and Multi-planets: Multi-Planets High Fe/H Favored. QuickTime™ and a Graphics decompressor are needed to see this picture. GJ 876 APF Webcam The APF Spectrometer A high resolution spectrometer optimized for ultra-precision radial velocity work • Constant gravity environment • Athermalized optical train • High efficiency (35%) l/Dl = 100,000 (for 1 arcsec slit) • Passively compensated space-frame • 1 m/s velocity precision • Cost: $2 million (NASA) Designed by Steve Vogt What We've Learned Giant Planets in Short Period & Eccentric Orbits Orbital Migration Eccentricity Excitation Multiple Planet Systems Importance of Resonances Statistics Frequency of Giant Planets within ~3 AU Mass-Period Distribution Function Correlations (Stellar Mass & Metallicity, Other Planets) Artwork courtesy of Sylwia Walerys New Questions Why did Jupiter stay… • At 5 AU? • In a circular orbit? Do most giant planets… • Migrate? • Have eccentric orbits? What limits… • Migration? • Eccentricity growth? Implications for terrestrial planets... • Formation? • Habitability? Artwork courtesy of Sylwia Walerys