HST Observations of White Dwarfs in the Globular Cluster NGC 6397

Abstract

White dwarfs (WDs) in globular clusters are the remnants of known and nearly equal-mass progenitors. The vast majority of those still bright enough to observe are the descendants of main sequence stars with masses not much more than that of the present cluster turnoff mass. This uniformity of origin makes cluster WDs of particular interest, and they have been prime targets for observation with the Hubble Space Telescope (HST). Significant numbers have been detected by several groups in at least six clusters (see, e.g.,Cool, Piotto, & King 1996, and references therein).

Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555.