H. E. Bond, Louisiana State University, writes that spectrograms obtained during Oct. 1974-Jan. 1976 show strong Ca II H and K emission lines and confirm the 2.8-day spectroscopic period (Bopp 1976, Inf. Bull. Variable Stars No. 1113). Hydrogen Balmer emission lines were observed on 1975 Nov. 13.27 UT, but they were absent or very weak the following night and not seen on any other spectrograms. Spectroscopic observations during the current season, to search for a recurrence of this phenomenon and possible correlation with radio activity (cf. IAUC 2929, 2972), would be desirable.
International Astronomical Union Circular
- Pub Date:
- September 1976