The properties of super-Earth atmospheres

Extrasolar super-Earths likely have a far greater diversity in their atmospheric properties than giant planets. Super-Earths (planets with masses between 1 and 10 Me) lie in an intermediate mass regime between gas/ice giants like Neptune and rocky terrestrial planets like Earth and Venus. While some super-Earths (especially the more massive ones) may retain large amounts of hydrogen either from accretion processes or subsequent surface outgassing, other super-Earths should have atmospheres composed of predominantly heavier molecules, similar to the atmospheres of the rocky planets and moons of our Solar System. Others still may be entirely stripped of their atmospheres and remain as bare rocky cores. Of the two currently known transiting super-Earths one (GJ 1214b) likely falls into the former category with a thick atmosphere, while the other (CoRoT-7b) falls into the latter category with a very thin or nonexistent atmosphere. I review some of the theoretical work on super-Earth atmospheres, and I present methods for determining the bulk composition of a super-Earth atmosphere.