Evidence for disc regulation in the lowest-mass stars of the young
  stellar cluster NGC 2264
  In the pre-main-sequence stage, star-disc interactions have been shown to
remove stellar angular momentum and regulate the rotation periods of stars with
M2 and earlier spectral types. Whether disc regulation also extends to stars
with later spectral types still remains a matter of debate. Here we present a
star-disc interaction study in a sample of over 180 stars with spectral types
M3 and later (corresponding to stellar masses $\leq 0.3 M_\odot$) in young
stellar cluster NGC 2264. Combining rotation periods from the literature, new
and literature spectral types, and newly presented deep Spitzer observations,
we show that stars with masses below 0.3 $M_\odot$ with discs also rotate
slower than stars without a disc in the same mass regime. Our results
demonstrate that disc-regulation still operates in these low-mass stars,
although the efficiency of this process might be lower than in higher-mass
objects. We confirm that stars with spectral types earlier and later than M2
have distinct period distributions and that stars with spectral types M5 and
later rotate even faster M3 and M4-type stars.
