SETI bioastro: Frequency of Debris Disks around Solar-Type Stars: First Results from a Spitzer/MIPS Survey

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Paper: astro-ph/0509199
Date: Wed, 7 Sep 2005 20:04:44 GMT (116kb)

Title: Frequency of Debris Disks around Solar-Type Stars: First Results from a
Spitzer/MIPS Survey

Authors: G. Bryden, C. A. Beichman, D. E. Trilling, G. H. Rieke, et al

Comments: 11 figures
\\
We have searched for infrared excesses around a well defined sample of 69 FGK
main-sequence field stars. These stars were selected without regard to their
age, metallicity, or any previous detection of IR excess; they have a median
age of ~4 Gyr. We have detected 70 um excesses around 7 stars at the 3-sigma
confidence level. This extra emission is produced by cool material (< 100 K)
located beyond 10 AU, well outside the ``habitable zones'' of these systems and
consistent with the presence of Kuiper Belt analogs with ~100 times more
emitting surface area than in our own planetary system. Only one star, HD
69830, shows excess emission at 24 um, corresponding to dust with temperatures
> 300 K located inside of 1 AU. While debris disks with Ld/L* > 10^-3 are rare
around old FGK stars, we find that the disk frequency increases from 2+-2% for
Ld/L* > 10^-4 to 12+-5% for Ld/L* > 10^-5. This trend in the disk luminosity
distribution is consistent with the estimated dust in our solar system being
within an order of magnitude, greater or less, than the typical level around
similar nearby stars.

\\ ( http://arXiv.org/abs/astro-ph/0509199 , 116kb)

• Previous message: LARRY KLAES: "SETI bioastro: Extrasolar planets and brown dwarfs around A-F type stars"

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