Shell episode of Pleione (BU Tau)

Abstract

Pleione is a well known shell star in the Pleiades cluster (HD 23862, m_v = 5.20, Sp.Type B8Vn + shell according to Abt and Levato (1978)). Its photometric variability was investigated by Sharov and Lyuty (1976) who collected all available photometric observations on the star. They observed a minimum in 1973 connected with a new shell outburst. In 1974 and 1975 Sharov and Lyuty observed the beginning of a slow increase in B and V. Hopp and Witzigmann (1980) observed BU Tau in B and V during 1977- 1980. Their observations showed that the shell outburst still goes on as the star has not returned to its normal maximum light.