UBVRI photometry of stars in Berkeley 86

The absence of current star formation, and the cluster's young age of about 6Myrs, leads to the conclusion that the initial mass function (IMF) and the current mass function are identical for stars with m<10m_{sun}_. In the range of 1.2-20m_{sun}_, an IMF with a slope of {GAMMA}=-1.3+/-0.3 is found.

This value agrees well with other recent determinations of young clusters IMFs which are close to the classical Salpeter IMF with {GAMMA}=-1.35. Sections of the IMF of Berkeley 86 that are significantly steeper, or flatter, are most likely the result of a dip in the star's mass distribution in the range of 3.5-10m_{sun}_. Similar dips may have led to steep IMFs over narrow mass ranges, as reported in the literature for some other clusters.