We appreciate the constructive comments and suggestions by the referee, Dr. A. Hatzes, that led to an improved version of this paper. KGS and SL acknowledge the financial support from the Austrian Science Foundation (FWF) under grants S7301-AST and S7302-AST and are grateful to M. Weber for reducing the 1997 spectroscopic data. RCD wishes to acknowledge the help of Drs. Mark Giampapa and Bernard Bopp. JBR acknowledges the financial support from the Natural Science and Engineering Research Council of Canada.
© European Southern Observatory (ESO) 1999
Online publication: June 18, 1999