The light variations of P Cygni over two distinct time intervals are discussed. On the basis of new photometric observations obtained between 1985 and 2000 we conclude that there are alpha Cygni-type micro-variations with a relatively stable period of ~17.3 days. There are also longer cycles of variation with P 100 d, so-called 100-day micro-variations, and with P 1500-1600 d, a short S Dor-type phase. On the basis of a new analysis of P Cygni's 17th century brightness variations and a comparison with the 19th century light curve of eta Carinae, it is estimated that the mass ejected during the 1600 and 1655 outbursts amounted to 2.6 10-2 Mo.
P Cygni 2000: 400 Years of Progress
- Pub Date:
- June 2001