We thank the referee Dr. De Medeiros for valuable remarks. The Nordic Optical Telescope is operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. Data from RADEN, SIMBAD, and VALD have been used in the paper. This research was partly supported by grants from the Centre for International Mobility (CIMO), Finland, and by grants R2Q000 and U1C000 from the International Science Foundation, and by grant A-05-067 from the ESO and C&EE Programme.
© European Southern Observatory (ESO) 1999
Online publication: June 6, 1999