The author would like to thank the referee, Dr. E.W. Guenther, for helpful comments, and Drs. S. Allain, J. Bouvier, L. Carrasco, C. Dougados, R. Mújica and E. Recillas, for allowing him to use the spectra of BP Tau prior to their publication.
© European Southern Observatory (ESO) 1999
Online publication: September 13, 1999