SO Colloquium: The transition between super-Earths and sub-Neptunes: Interior and atmosphere modelling of the low-mass planet population

Low-mass exoplanets are showing a diversity in their densities, ranging from silicate-dominated super-Earths to volatile-rich sub-Neptunes. We have developed a coupled interior-atmosphere model that estimates the composition and interior structure of super-Earths and sub-Neptunes assuming water and CO2 atmospheres. The applications of the model include the homogenous analysis of a sample of multi-planetary systems, as well as the assessment of the observability of emission spectra for rocky exoplanets with the James Webb Space Telescope. I will explain how their compositions connect to their possible formation site in the protoplanetary disk and their formation mechanisms, including atmospheric escape, and how we can break degeneracies with new atmospheric characterisation data.