Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-26T07:28:53.218Z Has data issue: false hasContentIssue false
  • English
  • Français

The evolutionary status of WNL stars

Published online by Cambridge University Press:  07 August 2017

Paul A. Crowther ,
Linda J. Smith  and
D. John Hillier
Paul A. Crowther
Affiliation:
1 Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT U.K.
Linda J. Smith
Affiliation:
1 Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT U.K.
D. John Hillier
Affiliation:
2Department of Physics and Astronomy, University of Pittsburgh, 3941 O'Hara Street, Pittsburgh, PA 15260, U.S.A.

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.

We discuss the evolutionary and mass loss implications of recent non-LTE analyses of late WN (WNL) stars in the Galaxy, LMC and M33 using the Wolf-Rayet standard model and address the observed dichotomy of WNL stars discussed by Moffat (1989). Individual subtypes belong to two distinct groups. We find that the single WNL+abs and WN7 stars evolve directly from very massive O stars (60–100 M⊙) with the former intimately related to extreme Of stars and found exclusively in the youngest clusters in our Galaxy. Conversely, the observational properties and chemistries of WN8-10 stars suggest that they are descended from lower initial mass progenitors (∼25–60 M⊙). These stars are either dormant LBVs (= WN9–10) or at a phase immediately after this stage (= WN8) although a previous RSG phase cannot be excluded. Included in this subgroup are the LMC and M33 Ofpe/WN9 stars, re-classified as WN9–10 since they appear to be genuine WN stars.

Keywords

stars: Wolf-Rayetatmospheresabundanceswindsmass-loss
Type
Session II - Model atmospheres for single Wolf-Rayet stars
Information
Symposium - International Astronomical Union , Volume 163: Wolf-Rayet Stars: Binaries, Colliding Winds, Evolution , 1995 , pp. 147 - 151
Copyright
Copyright © Kluwer 1995 

References

Blecha, A., Schaller, G., Maeder, A. 1992, Nature 360, 320 Google Scholar
Conti, P.S., Bohannan, B. 1989, in: Davidson, K., Moffat, A.F.J. & Lamers, H.J.G.L.M (eds.), Physics of Luminous Blue Variables, Proc. IAU Coll. No. 113 (Dordrecht: Kluwer), p. 297 Google Scholar
Crowther, P.A., Hillier, D.J., Smith, L.J. 1994a, A&A in press Google Scholar
Crowther, P.A., Hillier, D.J., Smith, L.J. 1994b, A&A in press Google Scholar
Crowther, P.A., Smith, L.J., Hillier, D.J., Schmutz, W 1994c, A&A in press Google Scholar
Hamann, W.-R. 1994, Sp. Sci. Rev. 66, 237 Google Scholar
Hillier, D.J. 1990, A&A 231, 116 Google Scholar
Howarth, I.D., Prinja, R.K. 1989, ApJ Suppl. 69, 527 Google Scholar
Lamers, H.J.G.L.M. 1987, in: Lamers, H.J.G.L.M. & de Loore, C.W.H. (eds.), Instabilities in Luminous Early-Type Stars (Dordrecht: Reidel), p. 99 Google Scholar
Lamers, H.J.G.L.M., Leitherer, C. 1993, ApJ 412, 771 Google Scholar
Langer, N., Hamann, W.-R., Lennon, M., Najarro, F., Pauldrach, A.W.A., Puls, J. 1994, A&A in press Google Scholar
Meynet, G., Maeder, A, Schaller, G., Schaerer, D., Charbonnel, C. 1994, A&A Suppl. 103, 97 Google Scholar
Moffat, A.F.J. 1978, A&A 68, 41 Google Scholar
Moffat, A.F.J. 1989, ApJ 347, 373 CrossRefGoogle Scholar
Prinja, R.K., Smith, L.J. 1992, A&A 266, 377 Google Scholar
Robert, C., Moffat, A.F.J, Bastien, P., Drissen, L., St-Louis, N. 1989, ApJ 347, 1034 Google Scholar
Smith, L.F., Meynet, G., Mermilliod, J-C. 1994, A&A in press Google Scholar
Smith, L.J., Crowther, P.A., Prinja, R.K. 1994, A&A 281, 833 Google Scholar
Stahl, O., Wolf, B., Klare, G., Cassatella, A., Krautter, J., Persi, P., Ferrari-Toniolo, M. 1983, A&A 127, 49 Google Scholar
Stahl, O., Wolf, B., Leitherer, C., Zickgraf, F.J., Krautter, J., de Groot, M. 1984, A&A 140, 459 Google Scholar
Stahl, O. 1986, A&A 164, 321 Google Scholar
Walborn, N.R. 1973, AJ 78, 1067 Google Scholar
Walborn, N.R. 1982, ApJ 256, 452 Google Scholar
Walborn, N.R. 1986, in: De Loore, C.W.H., Willis, A.J. & Laskarides, P. (eds.), Luminous Stars and Associations in Galaxies, Proc. IAU Symp. No. 116 (Dordrecht: Reidel), p. 185 Google Scholar