Characterizing a New Kind of Planet: Low-Mass Low-Density Exoplanets
|Date/Time:||Monday, 09 Sep 2013 from 4:10 pm to 5:00 pm|
NASA's Kepler Mission has revealed that the most common size of planet in our galaxy may be those from 2-3 Earth radii. Such medium-sized planets are significantly more common on close-in orbits than Neptune and Jupiter-class giant planets. We have no analog for these planets in our solar system. To explain their size, most require a thin envelope of H/He gas, atop a core of high pressure rock and/or water. An example relatively close to home is planet GJ 1214b, which is 2.6 Earth radii and 6 Earth masses, and orbits a cool red dwarf star near the Sun. This planet has been extensively studied with the Hubble and Spitzer Space Telescopes. In this talk I will first discuss our current understanding of the composition and atmospheric physics of GJ 1214b, which is potentially a prototype for this class of low-mass low-density planets. I will then describe the physical processes that may be common to this type of fascinating planets.
Jonathan Fortney is an Associate Professor in the Department of Astronomy & Astrophysics at the University of California, Santa Cruz. He models the interiors, atmospheres, and thermal evolution of diverse types of planets, focusing on planets both inside and outside the solar system. In 2010 he was the recipient of the Urey Prize from the Division for Planetary Sciences of the American Astronomical Society. He obtained his BS in Physics from Iowa State University in 1999 and his PhD in Planetary Sciences from the University of Arizona in 2004.