This research is based on observations made with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy Inc. under NASA contract NAS 5-26555. S. H. is supported by the Danish Centre for Astrophysics with the HST . P. C. acknowledges financial support from the Sherman M. Fairchild Foundation. The authors would like to thank Peter Stetson for kindly making his WFPC2 PSFs, and the DAOPHOT II software, available.
© European Southern Observatory (ESO) 1999
Online publication: July 26, 1999