Cool Stars 14 - Submitted Abstract # 93
This version created on 05 October 2006

Search for Cold Debris Disks around M-dwarfs


J.-F. Lestrade, Paris
M. C. Wyatt, Cambridge, UK 
F. Bertoldi, Bonn U.
W. R. F. Dent, UKATC
K. M. Menten, MPI Bonn

Debris disks are believed to be related to planetesimals left over
around stars after planet formation has ceased.  The frequency of
debris disks around M-dwarfs which account for 70% of the stars in the
Galaxy is unknown while constrains have already been found for A- to
K- type stars.  We have searched for cold debris disks around 32 field
M-dwarfs by conducting observations at lambda = 850  micron with the
SCUBA bolometer array camera at the JCMT and at lambda = 1.2mm with
the MAMBO array at the IRAM 30-m telescopes.  We have detected a new
debris disk around an M0.5 dwarf at lambda = 850  micron, providing
evidence for cold dust at large distance from this star (~300  AU).
By combining the results of our survey with the ones of Liu et al.
(2004), we estimate for the first time the frequency of cold debris
disks around field M-dwarfs with ages between 20  and 200~Myr.  This
frequency is 7 - 21 % in our sample and is consistent with the
frequency of cold debris disks (9 - 23 %) around A- to K-type main
sequence stars of the same age.  This is an indication that cold disks
may be equally prevalent across stellar spectral types.

----------------------------------