High State of Hα Emission Activity of the Herbig Be Star HD 200775

Abstract

We present the results of high-resolution spectroscopic observations of the pre–main-sequence Herbig Be star HD 200775 obtained between 1994 September and 1998 February. Strong variations of the Ha line associated with an extended period of strong emission during the summer and fall of 1997 have been observed. The line equivalent width took on the highest value reported in the last 20 yr. A review of the observational literature dating back to 1977 indicates periodic behavior of the Ha equivalent width with a period of 3.68 yr. These variations might be due to interaction between the stellar wind and the protostellar envelope, as suggested previously by Beskrovnaya et al., or to an effect of a possible close companion, such as those detected in some classical Be stars. The next high emission state is predicted to occur in the first half of 2001. We emphasize the importance of coordinated photometric and high-resolution spectroscopic observations for further understanding of the star’s behavior.