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 \mu m with the SCUBA bolometer array camera at the JCMT and at \lambda = 1.2 mm with the MAMBO array at the IRAM 30-m telescopes .
This is the first survey of a large sample of M-dwarfs conducted to provide statistical constraints on debris disks around this type of stars .
We have detected a new debris disk around the M0.5 dwarf GJ842.2 at \lambda = 850 \mu m , providing evidence for cold dust at large distance from this star ( \sim 300 AU ) .
By combining the results of our survey with the ones of Liu et al .
( 2004 ) , we estimate for the first time the detection rate of cold debris disks around field M-dwarfs with ages between 20 and 200Â Myr .
This detection rate is 13 ^ { +6 } _ { -8 } \% and is consistent with the detection rate 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 .