Hostname: page-component-7bb8b95d7b-dtkg6 Total loading time: 0 Render date: 2024-09-22T15:40:29.846Z Has data issue: false hasContentIssue false
  • English
  • Français

Chemical Composition in the Envelopes of Different WR Subtypes

Published online by Cambridge University Press:  03 August 2017

T. Nugis
T. Nugis*
Affiliation:
W. Struve Astrophysical Observatory of Tartu 202444 Tõravere Estonia, USSR

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.

Valuable model-independent information about the chemical composition of WR stars can be obtained by using lines of different ions arising at transitions between highly excited energy levels. We determine the abundances of He, H, C, N, O using theoretical line intensities obtained by solving statistical equilibrium equations for level populations for different subtype WR envelope conditions.

The chemical composition of WR stars strongly differs from the mean cosmic composition. In the case of WN stars nuclear processed CNO products of H-burning are revealed in the envelopes and He-burning products in the WC envelopes.

The abundance of oxygen in WC stars differs from the predictions of recent evolutionary calculations which account for the new 12C(α,γ) 16O reaction rate.

Type
Session II. Atmospheres
Information
Symposium - International Astronomical Union , Volume 143: Wolf–Rayet Stars and Interrelations with other Massive Stars in Galaxies , 1991 , pp. 75 - 80
Copyright
Copyright © Kluwer 1991 

References

References

Lucy, L.B. 1983, Ap. J., 274, 372.Google Scholar
Lucy, L.B., & White, R.L. 1982, Ap. J., 241, 300.Google Scholar
Owocki, S.P., Castor, J., & Rybicki, G.B. 1988, Ap. J., 335, 914.Google Scholar
Willis, A.J., Howarth, I.D., Smith, L.J., Garmany, C.D., & Conti, P.S. 1989, Astr. Ap. Suppl., 77, 269.Google Scholar

References

Barlow, M.J., Roche, P.E. and Aitken, D.K., 1988. M.N.R.A.S., 232, 821.CrossRefGoogle Scholar
Bhatia, A.K. and Underhill, A.B., 1988. Ap.J. Suppl. 67, 187.Google Scholar
Bhatia, A.K. and Underhill, A.B., 1986. Ap.J. Suppl. 60, 323.Google Scholar
Castor, J.I., 1970. M.N.R.A.S. 149, 111.CrossRefGoogle Scholar
Conti, P.C., Massey, P. and Vreux, J.-M., 1989. Preprint. Google Scholar
Langer, N. and El Eid, M.F., 1986. Astron. Astrophys. 167, 265.Google Scholar
Maeder, A., 1987, Astron. Astrophys. 173, 247.Google Scholar
Maeder, A., 1983, Astron. Astrophys. 120, 113.Google Scholar
Nugis, T., 1990. Astrofiz. 32, 85.Google Scholar
Nugis, T., 1989. Tartu Astrofüüs. Obs. Teated No 94, 3.Google Scholar
Prantzos, N., Doom, C., Arnould, M. and de Loore, C, 1986. Ap.J. 304, 695.CrossRefGoogle Scholar
Smith, L.F. and Hummer, D.G., 1988. M.N.R.A.S. 230, 511.CrossRefGoogle Scholar
Torres, A.V., 1988. Ap.J. 325, 759.Google Scholar
Torres, A.V., 1985. PhD thesis, JILA, University of Colorado.Google Scholar