LESIA - Observatoire de Paris

Structure, Composition and Habitability of super-Earths

Monday 8 February 2010, by Diana Valencia (Observatoire de la Cote d’Azur)

Monday 15 February 2010 à 11h00 , Lieu : Salle de conférence du bât. 17

Within the research field of exoplanets there is a new type of planets: super-Earths. These are planets voided of a massive atmosphere and thus resemble the Terrestrial Planets and Icy Satellites in the Solar System. The first generation of data comprises masses and radius and last year the first two transiting super-Earths were reported: CoRoT-7b and GJ1214b. I will discuss the composition of these two planets based on the data and internal structure models. While they are similar in mass, CoRoT-7b is small and thus may be terrestrial, while GJ1214b is larger and has a volatile-rich atmosphere. Despite a robust mass-radius relation for super-Earths, there is an intrinsic degeneracy in composition. I will present the limitations on what can be inferred from mass-radius measurements and future steps to disentangle valid compositions. In addition, a subset of the terrestrial super-Earths might have evolved to be habitable. I will present results on the thermal state and interior dynamics of these planets. Preliminary results show that a suitable mass range for planets to exhibit habitable conditions is 1-5 M_Earth.