The Open Cluster NGC 2437 (Messier 46)
  The stellar content of the open cluster NGC 2437 (Messier 46) is investigated
using moderately deep u*,g', and r' MegaCam images. When compared with solar
metallicity isochrones, the (g', u'-g') and (r', g'-r') CMDs are consistent
with an age log(t_yr) = 8.35 +/- 0.15, a distance modulus 11.05 +/- 0.05, and a
color excess E(B-V) = 0.115 +/- 0.035. The r' luminosity function (LF) of main
sequence stars in the magnitude range r' < 17 (i.e. masses > 0.8 solar) has a
shape that follows solar neighborhood star counts. However, at fainter
magnitudes the cluster LF is flat, in contrast with what would be expected from
solar neighborhood counts. The clustering properties of stars in NGC 2437 are
investigated by examining the two-point angular correlation functions of main
sequence stars in different brightness ranges. Main sequence stars fainter than
r' = 17 are less centrally concentrated than brighter stars and are found over
a larger area of the sky, suggesting that there is a corona of faint main
sequence stars around NGC 2437. Based on the flat LF and extended spatial
distribution of faint stars, it is concluded that NGC 2437 is actively shedding
stars with masses < 0.8 solar.
