Structure, composition, and mass-radius relationships of rocky exoplanets

Abstract

The growing number of transiting planet discoveries will allow us to characterize rocky exoplanets in terms of internal structure and atmospheric composition with important implications for their formation, orbital evolution, and possible habitability. We construct structural models of solid exoplanet interiors by using equations of state for the radial density distribution, which are compliant with the thermodynamics of the high-pressure limit. To some extent, those structural models suffer from inherent degeneracy or non-uniqueness problems because of a principal lack of knowledge of light and heavy constituents, their degree of internal separation, and/or the possible presence of an optically thick atmosphere. We thereby will address the robustness of mass-radius relationships and their usage for the classification of low-mass exoplanets and their characterization in terms of interior structure and bulk composition.