Characterization of the interior of giant exoplanets with JWST transit observations and a coupled atmosphere-interior model

A major challenge for exoplanet science is to understand the connection between the atmosphere and the interior of exoplanets in order to understand their origins, structure and evolution [Fortney et al. ]. The observed chemical composition can be affected by the conditions in the deep atmosphere (intrinsic temperature, vertical mixing, interaction with a magma ocean,…), while measuring the atmospheric composition can help to break some degeneracies in the interior of exoplanets. Atmosphere-interior retrievals combining spectroscopic data with mass and radius measurements have been successfully applied to JWST observations of the warm Neptune WASP-107 b [Sing et al. 2024, Welbanks et al. 2024]. They revealed a high internal heat flux and large core, with some differences between the two studies (Mcore=11.5+/-3 MEarth for Sing et al. 2024 and Mcore >22 MEarth for Welbanks et al. 2024).Here we use the coupled atmosphere-interior model called HADES [Wilkinson et al. 2024] to derive planetary properties (core mass, metallicity and intrinsic temperature) of giant exoplanets. First, we compare our results for WASP-107 b with previous measurements. Then we apply our model to a sample of giant exoplanets to derive trends with planetary mass and irradiation.ReferencesFortney et al., JGR Planets, 2021Sing et al., Nature, 2024Welbanks et al., Nature, 2024Wilkinson et al., A&A, 2024