IGPP Seminar Series

Using White Dwarfs to Study Extrasolar Planetary Material

by Michael Jura
UCLA Division of Astronomy and Astrophysics

Abstract

Evidence is strong that some white dwarfs are accreting tidally- disrupted asteroids. By measuring the abundances of heavy elements in the atmospheres of these stars, we indirectly measure the bulk composition of extrasolar planetary material. Like chondrites in the Solar System, extrasolar planets appear to be largely composed of oxides and metals, and they possess relatively little carbonaceous matter. Tentative evidence is put forward that the asteroid being accreted onto GD 40 experienced differentiation. We raise the possibility that the parent body being accreted onto GD 362 may have been as massive as Mars.
Tuesday, 21 April 2009
3853 Slichter Hall
Refreshments at 3:45 PM
Lecture at 4:00 PM