This is a particularly exciting time in the study of extrasolar planets.  We now know of hundreds of planets beyond the confines of our solar system, and we expect that thousands of these planets will be discovered within the next decade.  In my research, I study extrasolar planets from both an observational and a theoretical perspective:

Theoretical Work: 

Most of the exoplanets discovered to date are large gas giants.  However, observing capabilities have now advanced to the point where we are able to detect much smaller planets -- approaching the mass and size of the Earth itself.  So far more than 20 planets with masses (M sin i) less than 10 times that of the Earth have been discovered.  These planets, known as super-Earths seem to be quite common as evidenced by ground-based radial velocity surveys and by the Kepler mission, which searches a corner of the sky for planets that transit in front of their host stars.  The theoretical aspect of  my research involves developing computational models of the atmospheres of super-Earth exoplanets, in order to predict and diagnose their atmospheric structure and chemistry.  These models can be used to to aid in planning of future observations and instruments for exoplanet characterization.  They are also currently being used to interpret actual observations of super-Earth atmospheres. 

Observational Work:

Using the Grinnell College Gale Observatory telescope -- a 24” Cassegrain reflecting telescope built by DFM engineering -- I observe transiting extrasolar planets under the dark Iowan skies.  There are many opportunities for Grinnell College undergraduates to be involved in this work.  Please contact me if you are interested. 

Research Students:

John Kolpin -- UCSC


Theoretical Transmission Spectra for the Transiting Super-Earth GJ 1214b

(Miller-Ricci & Fortney 2010)

Artist’s conception of a super-Earth with a moon (Courtesy of Paul Kempton)