The authors are indebted to the referee F. Verbunt for his valuable suggestions. This research made use of the SIMBAD data base, operated by Centre de Données Stellaires in Strasbourg, France. We thank H.W. Dürbeck for important comments. NM thanks A. Bianchini and R. Claudi for having given him part of their observational time for the acquisition of the spectrum presented here, and A. Aloisi for useful suggestions on the advanced use of DAOPHOT II.
© European Southern Observatory (ESO) 1998
Online publication: February 4, 1998