Three-dimensional Exoplanet Characterization with ThERESA: Explorations in Chemistry and Cloud Properties

With the James Webb Space Telescope set to begin observing in the summer of 2022, spectroscopic eclipse observations will soon make three-dimensional characterization of exoplanet atmospheres possible. To enable these analyses, we developed ThERESA, a 3D exoplanet retrieval code. ThERESA builds 3D planet models from 2D eclipse maps, runs radiative transfer, and integrates over the planet at each observation time for simultaneous model comparison with all spectroscopic light curves. When applying ThERESA to synthetic observations of WASP-76b, we were able to recover the temperatures of the planet’s dayside, the eastward shift of the planet’s hotspot, and the existence and depth of the thermal inversion. We have extended ThERESA to vary chemistry and cloud properties within the model fitting, and discuss applications of these methods to synthetic light curves of clear and cloudy general circulation models, in preparation for JWST observations. ThERESA is open source and available for use by the community.