500K planet at 1.0, 0.5, 0.3 AU around a G2VBarman et al. (ApJ 556, 885, 2001)

Contrast Hot Jupiter vs planet at 5 AU

Hot Jupiter contrast to a G2 and M5Day side (substellar point)

PegasidesPegasides• Teq ~ 1250 K (Guillot et al. 1996)

- Jeans Evaporation without danger for the planet’s survival

- No mass transfer (atm < lobe de Roche)

• Rotation / revolution synch. : zonal winds > 1 km/s (Showman et Guillot 2002)

energy redistribution• Entire convective planet : evolution in 2 phases

1) rapid contraction Teff 2) slow cooling + insulation reduced thermal gradient (

Jupiter) external radiative zone + slowed gravitational contraction R > RJupiter

• Spectra : - Visible = reflected (Tbolo Teff)- IR = thermal emission - spectral signatures (Na, K, CO, H2O)- role of clouds (ex. silicates) (Baraffe et al. 2003)

Atmospheres and spectra of Atmospheres and spectra of giant exoplanetsgiant exoplanets

• Spectra determined by the chemical composition of the external atmosphere• BUT stars (hot) condensed species that contribute to the opacity:

- H20 solid, Fe solid- Enstatite, forsterite, CaTiO3

• Temperature (distance the star)

• Visual (reflected) + IR (thermal emission)

Classe Distance Teq Espèces dominantes remarques 1 qq u.a. < 150 K CH4, NH3 IR faible 2 1-2 u.a. 250 K H2O bandes de H2O 3 1 u.a. 350-800K H20, CH4, Na, K albedo faible

absence de nuages 4 0.1 u.a. 1000 K CO, Na, K, Li, Ru, H20 Silicates pas visibles 5 0.05 u.a. 1400 K H20, CO, nuages cf. après

Sudarsky et al., 2003

Gas giant spectraGas giant spectra

Sudarsky et al., 2003

This compares our TThis compares our Teffeff=100K, logg=3.0, model irradiated with the =100K, logg=3.0, model irradiated with the same flux as a particular set of models from Hubeny, Sudarsky, same flux as a particular set of models from Hubeny, Sudarsky, Burrows 2003. The difference between the dashed line and solid Burrows 2003. The difference between the dashed line and solid black lines is the presence (solid) and absence (dashed) of TiO & VO- black lines is the presence (solid) and absence (dashed) of TiO & VO- opacity.opacity.

Comparison to other model atmospheresComparison to other model atmospheres

Observational Observational ConstraintsConstraints

Na I D Observation Monochromatic radiusRp = 1.42 +0.1/-0.13 RJup

opacity stronger at

Charbonneau et al., 2002

- Weaker neutral Na concentration than expected ?

- High altitude clouds (reduces the limb size)

- departure from local thermodynamic equilibrium

Discussion about HD 209458 b’s radius: Cf. Allard Darwin Conf. 2003

Na I D et HD209458bNa I D et HD209458bBarman et al. (ApJ 569, L51, 2002)Barman et al. (ApJ 569, L51, 2002)

Left: Left: Monochromatic radius of HD209458b, based upon the Phoenix Monochromatic radius of HD209458b, based upon the Phoenix model atmospheres with Na in LTE (model atmospheres with Na in LTE (in blackin black) and ) and non-LTEnon-LTE..

Right: Right: Transit depth at wavelengths centered around the Na I D doublet, Transit depth at wavelengths centered around the Na I D doublet,

relative to the transit depth in adjacent bands, based upon the models on relative to the transit depth in adjacent bands, based upon the models on the left.the left. The points are observations by Charbonneau et al. (2002).The points are observations by Charbonneau et al. (2002).

Evolutionary Models for cool Brown Dwarfs and Extrasolar Giant Planets

Baraffe et al. (A&A 402, 701, 2003)

Evolutionary Models for cool Brown Dwarfs and Extrasolar Giant Planets

Baraffe et al. (A&A 402, 701, 2003)

Evolutionary Models for cool Brown Dwarfs and Extrasolar Giant Planets

Baraffe et al. (A&A 402, 701, 2003)

Emergent and reflected spectra (TEmergent and reflected spectra (Tintint=100K)=100K)

a=0.023AUa=0.023AUTTeqeq=2400K=2400K

a=0.046AUa=0.046AUTTeqeq=1700K=1700K

Compares the SEDs for HD209458b and OGLE-TR56b. Also shows Compares the SEDs for HD209458b and OGLE-TR56b. Also shows the pure reflected contributions for both. TR56b is closer and hotter the pure reflected contributions for both. TR56b is closer and hotter to the parent star and, therefore, a larger fraction of the optical to the parent star and, therefore, a larger fraction of the optical spectrum is due entirely to thermal reradiation of absorbed stellar spectrum is due entirely to thermal reradiation of absorbed stellar flux. This is not the case for HD.flux. This is not the case for HD.

Lyman Lyman observationobservation

-15% attenuation of Lyman during the transit (1.5% ofthe surface)

Vidal-Madjar et al., 2003

- Roche Lobe: R = 3.6 Rjup

at 8.5 R*

- If the Roche Lobe fills, 10% attenuation of Lyman

HH2 2 escapeescape

Texosphere Teq (Lammer, Selsis et al.)

PhasePhase

Temperature-Pressure (T-P) profile of HD209458b’s Temperature-Pressure (T-P) profile of HD209458b’s atmosphere for several concentric regions (lines of atmosphere for several concentric regions (lines of constant incident flux) around the substellar point. The constant incident flux) around the substellar point. The upper curve corresponds to the substellar point. The upper curve corresponds to the substellar point. The dotted curves correspond to regions intermédiate to dotted curves correspond to regions intermédiate to the substellar point and the terminator. The lowermost the substellar point and the terminator. The lowermost curve corresponds to the non-light hemispherecurve corresponds to the non-light hemisphere..

PerspectivesPerspectives

• Phase spectra, Global Atmospheric Circulation

• Thermal Escape, Gravitational Sedimentation, Photochemistry

• Sub- jovien and telluric Planet Atmospheres

Model atmospheres, thermal profiles, spectra and Model atmospheres, thermal profiles, spectra and synthetic photometry of Brown Dwarfs and Extrasolar synthetic photometry of Brown Dwarfs and Extrasolar Giant Planets (with and without stellar irradiation) are Giant Planets (with and without stellar irradiation) are available for all stages of evolution:available for all stages of evolution:http://perso.ens-lyon.fr/france.allard

Conclusions