Physical Society Colloquium

Examining the Interior Structure of Transiting Planets:
From Exo-Jupiters to Kepler's Super-Earths

Jonathan Fortney

University of California Santa Cruz

We have now reached the point in studying transiting planets that we can begin to examine the Jupiter-class planets as a class of astrophysical objects. At the same time, thanks to Kepler, the number of transiting planets below 10 Earth masses is now moving beyond just a handful. For the Jovians, we point out that there is an emerging population of planets that are relatively cool (Teff<1000 K) that appear to be unaffected by whatever is inflating the radii of the hottest members of this class. We have searched this cool group for correlations, and we find several interesting properties regarding the amount of heavy elements within these planets. For the lowest-mass planets, such as the 6-planet Kepler-11 system, signs point to an unexpectedly large populations of mini-Neptunes — low-mass, low-density planets with hydrogen-dominated envelopes. The Kepler-11 system may tell us much about the evaporation of the envelopes of these kinds of planets.