Cool Stars 14 - Submitted Abstract # 132
This version created on 05 October 2006

A Spitzer Survey for Debris Disks with Gas and Dust


Aki Roberge, NASA GSFC
Alycia Weinberger, Carnegie DTM

Long before the canonical debris disk Beta Pictoris was known to be a
young planetary system harboring evaporating and colliding
planetesimals, it had been classified as a "shell star." This peculiar
class consists of stars with narrow absorption lines and includes main
sequence stars with circumstellar gas.  It has turned out that some of
them are also surrounded by circumstellar dust disks.  The fraction of
main sequence shell stars which are actually debris disk systems is
not known, but seems to be at least 22%.  We have executed a Spitzer
MIPS photometric survey of 16 main sequence shell stars to determine
if they have infrared excess emission associated with a circumstellar
dust disk.  Preliminary analysis shows that at least 4 of them have
significant excess emission at both 24 and 70  microns.  If these
candidate stars are in fact edge-on debris disks, like Beta Pic, they
will be part of a rare and valuable set ideal for studying the
co-evolution of dust and gas through the terrestrial planet formation
phase.

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