Spectral similarities in the visible and UV spectrum of Herbig Ae/Be stars.

Abstract

High resolution spectroscopic observations of pre-main sequence Herbig Ae/Be stars in the P Cygni subclass are reported. The observations were carried out in order to determine whether the envelopes of the stars belonging to the same spectral subclass are similar. The specific stars observed were: HD 250550; BD 46 deg 3471, and HD 150193. The H-alpha line profiles of the stars are derived, and the obtained spectra are compared with published data on the spectra of AB Aur. It is shown that, in addition to the H-alpha profile, the stars exhibit similar spectra with respect to the Mg II resonance line, the Ca II K line, the Ca II infrared triplet line and the Na I D line. Since the lines are formed in distinct regions in the envelopes of the stars, the similarities would suggest that the envelopes of stars in the P Cygni subclass have the same structure. The possibility of categorizing envelopes structure in terms of specific stages of stellar evolution is briefly addressed.