Variations in the Spectrum of P Cygni
Abstract
An examination of spectrograms of P Cygni taken at the Lick and Mount Wilson observatories has shown that the Balmer lines in this star consist of an emission com- ponent and two absorption components, instead of one, as formerly supposed. These two absorption components vary in intensity (and probably in position) in such a way that on some occasions both are visible, while on others only one or the other is to be seen. No period for the variation can be deduced from the available material, but it is demonstrated that significant changes have occasionally occurred within intervals of the order of one month. The helium lines also appear to pass through a similar cycle in step with those of hydrogen
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1936
- DOI:
- 10.1086/143765
- Bibcode:
- 1936ApJ....84..296W