Hostname: page-component-68945f75b7-72kh6 Total loading time: 0 Render date: 2024-08-05T21:19:23.143Z Has data issue: false hasContentIssue false

On the Chemical Composition of Wolf-Rayet Stars

Published online by Cambridge University Press:  14 August 2015

T. Nugis*
Affiliation:
W. Struve Tartu Astrophysical Observatory, Estonian S.S.R., U.S.S.R.

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The chemical composition of 5 WR stars in Cygnus are considered by using the quasi-nebular variant of Beals' model. On the basis of the general considerations which follow from this model it was concluded that the C/He ratio for the WC stars appears to be more than 10 times higher than for normal OB stars and the N/He ratio in the case of the WN stars seems also to be somewhat higher than for normal OB stars. From the solution of the equations of statistical equilibrium for the level populations, it was found that in the case of the WC stars C/He≈1 and in the case of the WN stars N/He≈0.05–0.1. For the star HD 192163 (WN6) it was found that He/H≈4.2–7.3 and for the other stars He/H≳10.

Type
Part 5 / Wolf-Rayet Stars
Copyright
Copyright © Reidel 1975 

References

Aldrovandi, S. M. and Péquignot, D. A.: 1973, Astron. Astrophys. 25, 137.Google Scholar
Flower, D. F.: 1968, in Osterbrock, D. E. and O'Dell, R. C. (eds.), ‘Planetary Nebulae’, IAU Symp. 34, 205.Google Scholar
Henry, R. J.: 1970, Astrophys. J. 161, 1153.Google Scholar
Hidalgo, M. B.: 1968, Astrophys. J. 153, 891.Google Scholar
Ilmas, M. and Nugis, T.: 1973, Tartu Teated 44, 19.Google Scholar
Nugis, T.: 1973a, Tartu Teated 44, 83.Google Scholar
Nugis, T.: 1973b, Tartu Teated 44, 53.Google Scholar
Nugis, T. and Feklistova, T.: 1973, Tartu Teated 44, 145.Google Scholar
Rublev, S. V.: 1972, Izv. Spets. Astrofiz. Obs. 4, 3.Google Scholar
Rublev, S. V.: 1964, Astron. Zh. 40, 223.Google Scholar
Smith, L. F.: 1973, in Bappu, M. and Sahade, J. (eds.), ‘Wolf-Rayet and High-Temperature Stars’, IAU Symp. 49, 15.Google Scholar
Underhill, A. B.: 1973, in Bappu, M. and Sahade, J. (eds.), ‘Wolf-Rayet and High-Temperature Stars’, IAU Symp. 49, 237.Google Scholar