Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-26T03:27:36.391Z Has data issue: false hasContentIssue false
  • English
  • Français

Some Properties of Hot, High-Gravity, Pure Helium Atmospheres

Published online by Cambridge University Press:  12 April 2016

F. Wesemael  and
H.M. Van Horn
F. Wesemael
Affiliation:
Department of Physics and Astronomy and C.E.K. Mees Observatory, University of Rochester
H.M. Van Horn
Affiliation:
Department of Physics and Astronomy and C.E.K. Mees Observatory, University of Rochester

Extract

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.

Model atmosphere analyses of white dwarf spectra have contributed significantly to our understanding of the properties of degenerate stars.: In particular, the pioneering investigations of Bues (1970), Strittmatter and Wickramasinghe (1971) and Shipman (1972) have provided the first reliable determinations of the effective temperature and surface gravity of these objects (see Shipman 1979 and Weidemann 1978 for recent results). We now know with certainty that the hydrogen-rich white dwarf sequence extends at least over the range Te ∽ 6000 – 60.000K. In contrast, the hottest identified helium-rich white dwarfs seem to reach Te ~ 25.000K only, a puzzling result since the progenitors of DB white dwarfs should presumably also be helium-rich.

Type
Colloquium Session II
Information
International Astronomical Union Colloquium , Volume 53: White Dwarfs and Variable Degenerate Stars , August 1979 , pp. 125 - 129
Copyright
Copyright © The University of Rochester 1979

References

Auer, L.H. and Mihalas, D. 1969, Ap.J., 158, 641.CrossRefGoogle Scholar
Auer, L.H. 1972, Ap.J. Suppl. 24, 193.CrossRefGoogle Scholar
Barnard, A.J. and Cooper, J. 1970, J. Quant. Spectrosc. Radiat. Transfer, 10, 695.CrossRefGoogle Scholar
Barnard, A.J., Cooper, J. and Smith, E.W. 1974, J. Quant. Spectrosc. Radiat. Transfer, 14, 1025.Google Scholar
Barnard, A.J., Cooper, J. 1975, J. Quant. Spectrosc. Radiat. Transfer, 15, 429.CrossRefGoogle Scholar
Bues, I. 1970, Astr. Ap., 7, 91.Google Scholar
Green, R.F. 1977, Ph.D. thesis, California Institute of Technology.Google Scholar
Green, R.F. and Liebert, J.W. 1979, these proceedings.Google Scholar
Griem, H.R. 1974, Spectral Line Broadening by Plasmas (New York: Academic Press).Google Scholar
Koester, D., Liebert, J. and Hege, E.K. 1979, Astr. Ap. 71, 163.Google Scholar
Liebert, J., Beaver, E.A., Robertson, J.W., and Strittmatter, P.A. 1976, Ap.J. (Letters) 204, L119.Google Scholar
Mihalas, D., Heasley, J.N. and Auer, L.H. 1975, NCAR Technical Report 104.Google Scholar
Shamey, L.J. 1969, Ph.D. thesis, University of Colorado.Google Scholar
Shipman, H.L. 1972, Ap.J. 177, 723.Google Scholar
Shipman, H.L. 1979, Ap. J. 228, 240.Google Scholar
Strittmatter, P.A. and Wickramasinghe, D.T. 1971, M.N.R.A.S. 152, 47.CrossRefGoogle Scholar
Wegner, G. 1978, M.N.R.A.S. 187, 17.CrossRefGoogle Scholar
Weidemann, V. 1978, in The HR Diagram, ed. Davis Philip, A.G. and Hayes, D.S. (Dordrecht: Reidel), p. 121.CrossRefGoogle Scholar
Wesemael, F. 1979, Ph.D. thesis, University of Rochester.Google Scholar
Wesemael, F., Auer, L.H., Van Horn, H.M. and Savedoff, M.P. 1979, submitted to Ap.J.Google Scholar
Wesemael, F. and Van Horn, H.M. 1979, in preparation.Google Scholar
Wray, J.D., Parsons, S.B. and Henize, K.G. 1979, preprint.Google Scholar