Cool Stars 14 - Submitted Abstract # 357
This version created on 05 October 2006

Indirect Constraints on Terrestrial Planets Orbiting White Dwarfs


M. Jura, UCLA

There is good evidence that carbon-deficient tidally-disrupted
asteroids, occasionally even as massive as Ceres, have been accreted
onto at least 7% of the white dwarfs in the Solar neighborhood.  The
same stars which accrete asteroids probably also harbor planets.
Accretion of a terrestrial planet onto a white dwarf produces notable
infrared, optical and X-ray signatures.  Very tentatively, it seems
that the ratio of asteroid-accreting white dwarfs to
terrestrial-planet accreting white dwarfs is larger than 20,000.
Either terrestrial planets are rare, or it is very difficult compared
to asteroids to perturb planets into fatal orbits, an indirect
constraint on the architecture and evolution of planetary systems.  

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