Continuum Energy Distribution of Bright Be Stars

Abstract

This paper presents the spectrophotometric observations of five Be stars belonging to spectral type from B2.5 to B5 and luminosity class from III to V. The continuum energy distribution data of these stars are extracted from the spectrophotometric measurements over the wavelength range of λλ 3200-8000Å. The observed data of continuum energy distribution are compared with the theoretical energy distribution curves to derive the value of effective temperatures of these stars. We have also examined the effect of circumstellar envelopes of Be stars on their continuum energy distribution. It has been found that the extended circumstellar envelope of Be stars affect the underlying continua in the near-ultraviolet and near-infrared regions. Three Be stars are found to exhibit near-ultraviolet and near-infrared flux deficiency in their continua. For one of the Be, namely star HR 1289, we report the first continuum energy distribution measurements. Another normal B star HR 1363, which was observed as comparison star, was found to exhibit near-ultraviolet and near-infrared excess emission, which are signatures of a Be star, thus putting this star in the category of Be stars.