Spectral observations of Of and Wolf-Rayet stars in the 0.8 - 1.1 µ range.
Abstract
Summary. Spectra of twenty one 0 (mainly Of) and ten Wolf-Rayet stars have been obtained between 7000 A and 12000 A with a dispersion of 230 A mm 1 The present paper deals with the 0 spectra; the WR ones are given for comparison. Our sample of 0 stars shows that if high temperature and low gravity are highly favorable for emission of He i10830, they are not however cither necessary or sufficient conditions to ensure emission of this line. In the spectra of HD 108, the width of this line exhibits a spectacular variation (a factor 2 at least) between August and November 1974. He II 10124 never is clearly visible. P generally appears as a weak absorption line, but is in emission on the spectra of HD 108 in November 1974. C iii 9713 never is a strong emission, even when both C ii' 5696 and C ii' 4649 are emission lines: this means that the mechanism pushing C iii 4649 into emission is not as simple as suggested by Nussbaumer Key words: Of Wolf-Rayet - infrared
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- June 1975
- Bibcode:
- 1975A&A....41..133A