Unveiling the atmospheres of giant exoplanets with an EChO-class mission

Abstract

More than a thousand exoplanets have been discovered over the last decade. Perhaps more excitingly, probing their atmospheres has become possible. With current data we have glimpsed the diversity of exoplanet atmospheres that will be revealed over the coming decade. However, numerous questions concerning their chemical composition, thermal structure, and atmospheric dynamics remain to be answered. More observations of higher quality are needed. In the next years, the selection of a space-based mission dedicated to the spectroscopic characterization of exoplanets would revolutionize our understanding of the physics of planetary atmospheres. Such a mission was proposed to the ESA cosmic vision program in 2014. Our paper is therefore based on the planned capabilities of the Exoplanet Characterization Observatory (EChO), but it should equally apply to any future mission with similar characteristics. With its large spectral coverage ($4-16\mu \mathrm{m}$), high spectral resolution ($\Delta \lambda /\lambda >300$ below $5\mu \mathrm{m}$ and $\Delta \lambda /\lambda >30$ above $5\mu \mathrm{m}$) and $1.5\mathrm{m}$ mirror, a future mission such as EChO will provide spectrally resolved transit lightcurves, secondary eclipses lightcurves, and full phase curves of numerous exoplanets with an unprecedented signal-to-noise ratio. In this paper, we review some of today's main scientific questions about gas giant exoplanets atmospheres, for which a future mission such as EChO will bring a decisive contribution.

Accepted to the Experimental Journal of Astronomy

References in corpus (22)

• Rayleigh scattering in the transit spectrum of HD 189733b
• Can TiO Explain Thermal Inversions in the Upper Atmospheres of Irradiated Giant Planets?
• Atmospheric Sulfur Photochemistry on Hot Jupiters
• Theoretical Spectra and Light Curves of Close-in Extrasolar Giant Planets and Comparison with Data
• Inflating Hot Jupiters With Ohmic Dissipation
• Multi-Wavelength Constraints on the Day-Night Circulation Patterns of HD 189733b
• Dynamics and Disequilibrium Carbon Chemistry in Hot Jupiter Atmospheres, With Application to HD 209458b
• Atmospheric Circulation of Hot Jupiters: Three-dimensional circulation models of HD 209458b and HD 189733b with Simplified Forcing
• Heat transport in giant (exo)planets: a new perspective
• Atmospheric Circulation of Hot Jupiters: A Shallow Three-Dimensional Model
• Atmospheric Dynamics of Short-period Extra Solar Gas Giant Planets I: Dependence of Night-Side Temperature on Opacity
• Atmospheric Circulation of Eccentric Hot Neptune GJ436b
• Pseudo 2D chemical model of hot Jupiter atmospheres: application to HD 209458b and HD 189733b
• A non-grey analytical model for irradiated atmospheres. I: Derivation
• Constraining Exoplanet Mass from Transmission Spectroscopy
• TiO and VO broad band absorption features in the optical spectrum of the atmosphere of the hot-Jupiter HD209458b
• A New 24 micron Phase Curve for upsilon Andromedae b
• Magnetic Effects in Hot Jupiter Atmospheres
• Determining atmospheric conditions at the terminator of the hot-Jupiter HD209458b
• Magnetohydrodynamic Simulations of the Atmosphere of HD 209458b
• Ohmic Dissipation in the Interiors of Hot Jupiters
• An analysis of the CoRoT-2 system: A young spotted star and its inflated giant planet

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• Atmospheric Dynamics of Hot Giant Planets and Brown Dwarfs
• Exoplanet phase curves: observations and theory
• Hot Jupiter Diversity and the Onset of TiO/VO Revealed by a Large Grid of Non-Grey Global Circulation Models
• The THOR+HELIOS general circulation model: multi-wavelength radiative transfer with accurate scattering by clouds/hazes
• Global Chemistry and Thermal Structure Models for the Hot Jupiter WASP-43b and Predictions for JWST