CIRCUMSTELAR PECULIARITIES OF THE HERBIG AE/BE STARS DERIVED FROM HIGH-RESOLUTION SPECTROSCOPY

Abstract

An overview of the results of spectroscopic observations of the Herbig Ae/Be stars at different observatories starting from 1986 in the framework of the Pulkovo program is presented. The aim of the program is to study structural, kinematical and physical properties of the circumstellar envelopes around bright objects from the catalogue of candidates to the Herbig Ae/Be stars
by Thé et al. (1994). As a result, long-term spectroscopic monitoring of 10 Herbig Ae/Be stars have been carried out. Two main groups of the program objects can be distinguished. The first group includes three yearly type (B0–B3) massive star. All of them have been found to be binary systems and demonstrate some unusual inexplicable phenomena. The second group contains B9–A4 stars with signatures of dense outflowing matter on the line-of-sight between the star and the observer. The analysis of their
spectroscopic variability allows to investigate structural and kinematical features of their circumstellar envelopes. A special case is the B6e Herbig star HD259431. There is good reason to believe that this object is surrounded by a magnetosphere, that is in contrary with earlier predictions by other investigators.