R. Poeckert, Dominion Astrophysical Observatory, and A. F. Gulliver, University of Alberta, report: "Spectrograms obtained at the DAO indicate that omicron And (HD 217675) may be entering a shell episode. On 1980 May 4 H-beta, H-gamma, Mg II 448.1 nm, Si II 412.8 and 413.1 nm showed narrow weak (~ 4 percent of continuum) absorption components. On June 18 H-alpha had a central depth 25 percent higher than normal, indicating a partial filling in of the photospheric line (by envelope emission?). Spectroscopic, photometric and polarimetric observations of omicron And should be initiated promptly."
International Astronomical Union Circular
- Pub Date:
- July 1980