Brown Bag Colloquium: Dr. Nikku Madhusudhan

Monday, Apr 8, 2013
12:00 pm
Location: Kuiper Space Sciences
Room: 309

Dr. Nikku Madhusudhan
Postdoctoral Fellow
Yale University

Host: Ilaria Pascucci

Super-Earth Interiors


Latest exoplanet surveys are revealing an abundance of low mass exoplanets in the galaxy. Besides hundreds of candidates discovered by the Kepler space telescope, masses and radii have been measured for about ten confirmed `super-Earths', exoplanets with masses between 1 and 10 Earth masses. Being closest analogs to rocky planets in the solar system, detailed characterization of super-Earths is one of the frontier areas of exoplanet science today. In this talk, I will present the latest constraints emerging on the interior structures and formation environments of currently known super-Earths. Their interiors span a wide range of compositions, from water worlds with thick volatile envelopes to super-Mercuries, lava planets, and diamond planets, testing the limits of our understanding of mineralogies and equations of state under exotic conditions. These constraints are made possible by precise measurements of masses, radii, and spectra of super-Earths, and elemental abundances of their host stars, together with new modeling techniques. I will discuss a new and comprehensive modeling approach which includes hybrid models of super-Earth interiors and non-gray atmospheres, as well as cosmochemistry of their formation environments. I will present a comparative analysis of several transiting super-Earths and will focus particularly on two super-Earths (GJ 1214b and 55 Cancri e) which represent distinct end-members in the thermo-chemical phase space. The implications of our results for the diversity of geochemical, geophysical, and astrobiological conditions on super-Earths will be discussed. I will outline key questions that define the future of super-Earth characterization, along with new avenues for theoretical, observational, and experimental efforts.