A common proper motion survey of M dwarf stars within 8 pc of the Sun reveals no new stellar or brown dwarf companions at wide separations ( \sim 100-1400 AU ) .
This survey tests whether the brown dwarf “ desert ” extends to large separations around M dwarf stars and further explores the census of the solar neighborhood .
The sample includes 66 stars north of -30 \arcdeg and within 8 pc of the Sun .
Existing first epoch images are compared to new J -band images of the same fields an average of 7 years later to reveal proper motion companions within a \sim 4 arcminute radius of the primary star .
No new companions are detected to a J -band limiting magnitude of \sim 16.5 , corresponding to a companion mass of \sim 40 Jupiter masses for an assumed age of 5 Gyr at the mean distance of the objects in the survey , 5.8 pc .