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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

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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

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