Planetary Sizes Dimitar Sasselov Harvard-Smithsonian Center for Astrophysics

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

 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

 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

Mass-Radius diagram: Konacki, Torres, Sasselov, Jha (2005) All known transiting extra-solar planets

 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:

OGLE-TR-113b Transit Light Curve Radial Velocities OGLE: Udalski et al. (2003) P = 1.43 days I = 14.4 mag

Stellar Mass and Age: Stellar evolution track for 3 metallicities and Helium content: Stars evolve from bottom zero-age main sequence HD Our Sun Lines of constant stellar radii Cody & Sasselov (2002) Age = 7 Gyrs

 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:

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

Improved photometry: Holman (2004) Magellan telescope

Improved photometry: Moutou, Pont, Bouchy, Mayor (2004) VLT telescope OGLE-TR-132b Original OGLE light curve

Improved photometry: Charbonneau, Brown, Gilliland, Noyes (2004) Hubble Space Telescope - STIS HD b Wavelength- dependent limb darkening allows more accurate R P and R S determination

Mass-Radius diagram: Konacki, Torres, Sasselov, Jha (2005) Models of the interior: Overall Z; Core vs. no-core; Age.

 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

Phase diagram (hydrogen): Guillot (2005)

 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

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

Saturn’s core mass and mass of heavy elements : Interiors of Giant Planets Saumon & Guillot (2004)

 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

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

 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

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

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.

 Super-Earths (1-10 M earth )  Are they there ?  What is their Mass-Radius relation(s)  Detection  Doppler shifts  Transits Interiors of Super-Earths

Formation and survival of large terrestrial planets: Interiors of Super-Earths Ida & Lin (2004) All evidence is that they should be around:

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

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

The Earth is the only planet model that has a liquid outer core: Interiors of Super-Earths

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