The author would like to thank especially David L. Lambert and Eric Bakker for obtaining high resolution spectra of the program stars at his request and for helpful discussions. Additional helpful comments were provided by Suchitra Balachandran, Don Brownlee, Jocelyn Tomkin, George Wallerstein, and the anonymous referee. Thanks also go to Chris Sneden for use of his abundance analysis code and Robert Kurucz for use of his model atmospheres. This research has made use of the Simbad database, operated at CDS, Strasbourg, France. The research has been supported in part by the National Science Foundation (Grant AST-9315124), the Robert A. Welch Foundation of Houston, Texas, and the Kennilworth Fund of the New York Community Trust.
© European Southern Observatory (ESO) 1998
Online publication: May 12, 1998