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The PG1159 Variables

Published online by Cambridge University Press:  30 March 2016

Arthur N. Cox
Arthur N. Cox*
Affiliation:
University of California, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545

Extract

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The PG1159 variables, named after the variable of that number in the Palomar-Green blue star catalogue, have high luminoisites, high surface temperatures, and high gravities. Their masses, however, must be the normal low value of 0.6 solar mass because they are the direct antecedents of the classical DB white dwarfs. In every case, they seem to have no hydrogen at all in their atmospheres, but significant helium, carbon, and oxygen is present (Sion, Liebert, and Starrfield 1985). Table 1 gives a list of these stars of which most, but not all, show light variations indicative of nonradial low degree, but probably high order, g modes.

Type
Joint Discussions
Information
Highlights of Astronomy , Volume 7: Highlights of Astronomy. As presented at the XIXth General Assembly of the IAU, 1985 , 1986 , pp. 229 - 236
Copyright
Copyright © Reidel 1986

References

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