We present results of a high-resolution , near-infrared survey of 41 nearby , young ( \lesssim 300 \mathrm { Myr } ) M0–M5.0 dwarfs using the Altair natural guide star adaptive optics system at the Gemini North telescope .
Twelve of the objects appear to be binaries , 7 of which are reported here for the first time .
One triple system was discovered .
Statistical properties are studied and compared with earlier ( F to K ) and later ( \geq M6 very low-mass , VLM ) populations .
We find that the separation distribution of the binaries in this sample peaks at 13 ^ { +14 } _ { -9 } \mathrm { AU } , which is consistent with previous measurements of early-M binaries .
Hence , early-M binaries seem to occur in—on average—tighter systems than G binaries .
At the same time they are significantly wider than field VLM binary stars .
The distribution of mass ratios q of primary and secondary stars was found to show an intermediate distribution between the strongly q \rightarrow 1 peaked distribution of field VLM systems and the almost flat distribution of earlier-type stars .
Consequently , we show evidence for relatively young , early-M binaries representing a transition between the well known earlier star distributions and the recently examined field VLM population characteristics .
Despite the fact that this survey was dedicated to the search for faint brown dwarf and planetary mass companions , all planetary mass candidates were background objects .
We exclude the existence of physical companions with masses greater than 10 Jupiter masses ( \mathrm { M _ { Jup } } ) at separations of \gtrsim 40 \mathrm { AU } and masses greater than 24 \mathrm { M _ { Jup } } for separations \gtrsim 10 \mathrm { AU } around 37 of the 41 observed objects .