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Planetary Sizes Dimitar Sasselov Harvard-Smithsonian Center for Astrophysics
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Some of the Hot Jupiters do not match well models based on Jupiter & Saturn: More diversity than expected ?... Gaudi (2005) w Bodenheimer et al.(2003), Laughlin et al. (2005) models
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Mass-Radius Diagram of Extrasolar Planets Transiting Planets: observational precision Planet Ages < Stellar Ages Interior Models: Jupiter & Saturn The Equation of State Chemical composition Implications for Hot Jupiters & Planet Formation Smaller Planets: Sizes of Super-Earths Summary Talk Plan
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Precise massive photometry: OGLE Survey: 5 transiting planets (10b, 56b, 111b, 113b, 132b) TrES Survey: 1 transiting planet (TrES-1) New parameters: Radius & Mean Density The Mass-Radius diagram Know inclination, hence Mass & Radius are accurate; Internal structure; insights into planet formation. On-Off Photometry Atmospheric transmission in spectral lines; Measurement of planet’s daytime IR thermal emission Photometry of Extrasolar Planets
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Mass-Radius diagram: Konacki, Torres, Sasselov, Jha (2005) All known transiting extra-solar planets
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In Mass: What we derive is: M P sini M S -2/3 Transit phase helps in getting a good RV amplitude Know inclination, as well Use stellar models for M S In Radius: With one-band photometry - depends on M S and R S Good multi-band photometry - drop dependence on R S The Measurement Errors:
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OGLE-TR-113b Transit Light Curve Radial Velocities OGLE: Udalski et al. (2003) P = 1.43 days I = 14.4 mag
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Stellar Mass and Age: Stellar evolution track for 3 metallicities and Helium content: Stars evolve from bottom zero-age main sequence HD 209458 Our Sun Lines of constant stellar radii Cody & Sasselov (2002) Age = 7 Gyrs
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In Mass: What we derive is: M P sini M S -2/3 Transit phase helps in getting a good RV amplitude Know inclination, as well Use stellar models for M S In Radius: With one-band photometry - depends on M S and R S Good multi-band photometry - drop dependence on R S The Measurement Errors:
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OGLE-TR-10b Transit Light Curve Radial Velocities Konacki, Torres, Sasselov, Jha (2005), green & brown points: Bouchy, Pont, Melo, Santos, Mayor, Queolz & Udry (2004) OGLE: Udalski et al. (2002) P = 3.10 days V = 14.9 mag
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Improved photometry: Holman (2004) Magellan telescope
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Improved photometry: Moutou, Pont, Bouchy, Mayor (2004) VLT telescope OGLE-TR-132b Original OGLE light curve
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Improved photometry: Charbonneau, Brown, Gilliland, Noyes (2004) Hubble Space Telescope - STIS HD 209458b Wavelength- dependent limb darkening allows more accurate R P and R S determination
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Mass-Radius diagram: Konacki, Torres, Sasselov, Jha (2005) Models of the interior: Overall Z; Core vs. no-core; Age.
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Our own Solar System: Jupiter & Saturn Constraints: M, R, age, J 2, J 4, J 6 EOS is complicated: mixtures of molecules, atoms, and ions; partially degenerate & partially coupled. EOS Lab Experiments: Laser induced - LLNL-NOVA Gas gun (up to 0.8 Mbar only) Pulsed currents - Sandia Z-machine Converging explosively-driven - Russia (up to 1.07 Mbar) Interiors of Giant Planets
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Phase diagram (hydrogen): Guillot (2005)
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EOS Experiment Breakthrough ? Russian Converging explosively-driven system (CS) Boriskov et al. (2005) matches Gas gun & Pulsed current (Z-machine) results deuterium is monatomic above 0.5 Mbar - no phase transition consistent with Density Functional Theory calculation (Desjarlais) Interiors of Giant Planets
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Jupiter’s core mass and mass of heavy elements : Interiors of Giant Planets Saumon & Guillot (2004) The heavy elements are mixed in the H/He envelope
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Saturn’s core mass and mass of heavy elements : Interiors of Giant Planets Saumon & Guillot (2004)
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Core vs. No-Core: How well is a core defined? Saturn: metallic region can mimic ‘core’ in J 2 fit (Guillot 1999); Core dredge-up - 20 M earth in Jupiter, but MLT convection… ? Overall Z enrichment: Jupiter - 7x solar Saturn - 6x solar both have high C/O ratio Interiors of Giant Planets
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Some of the Hot Jupiters seem to have too large, or too small, sizes: More diversity than expected ?... Gaudi (2005) w Bodenheimer et al.(2003), Laughlin et al. (2005) models
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Core vs. No-Core: Core - leads to faster contraction at any age; the case of OGLE-TR-132b > high-Z and large core? Evaporation - before planet interior becomes degenerate enough - implications for Very Hot Jupiters; Cores: nature vs. nurture ? - capturing planetesimals Overall Z enrichment: larger size, but only during first 1-3 Gyrs (opacity effects vs. molecular weight effects) Interiors of Hot Jupiters
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Core-less Very Hot Jupiters could lose all their mass, if parked so close early… Interiors of Hot Jupiters DS (2003) w updates They could also capture high-Z planetesimals ? OGLE-TR-56b has: V orb = 202 km/sec, V esc = 38 km/sec. Very Hot Jupiters
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Dayside thermal emission: Seager et al. (2005) Atmospheric models for the two transiting Hot Jupiters: TrES-1 & HD209458b. Best fits for both CO and H 2 O seem to need high C/O values.
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Super-Earths (1-10 M earth ) Are they there ? What is their Mass-Radius relation(s) Detection Doppler shifts Transits Interiors of Super-Earths
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Formation and survival of large terrestrial planets: Interiors of Super-Earths Ida & Lin (2004) All evidence is that they should be around:
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The models follow the techniques and many assumptions of Earth’s model: Interiors of Super-Earths Valencia, O’Connell, Sasselov (2005) The mantle is taken to be convecting as a single layer. Schematic temperature profile
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Mass-Radius relations for 11 different mineral compositions: Interiors of Super-Earths Valencia, O’Connell, Sasselov (2005) 1M E 2M E 5M E 10M E
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The Earth is the only planet model that has a liquid outer core: Interiors of Super-Earths
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Summary Some basic question about the formation and structure of Hot Jupiters and other extrasolar planets remain unresolved The Mass-Radius diagram Multi-band photometry, esp. in near-IR and mid-IR Main observational results in next few years will likely all come from precise photometry Discovery of more and smaller planets: COROT (2006) KEPLER (2007) Characterization: HST & MOST (visible) Spitzer (IR) Stellar Connection: better masses, radii, and ages of the planets
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