title: A Maximum Radius for Habitable Planets.
abstract: We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope.
authors.affiliation: Center for Space and Habitability, Physikalisches Institut, Universität Bern, Bern, Switzerland, yann.alibert@space.unibe.ch.
authors.forename: Yann
authors.initials: Y
authors.lastname: Alibert
mesh_terms: D019419:Evolution, Planetary; D018559:Exobiology; D005118:Extraterrestrial Environment; D007053:Ice; D008962:Models, Theoretical; D000069497:Origin of Life; D016083:Planets; D011312:Pressure; D013696:Temperature
chemical_list: D007053:Ice