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Peculiar Red Giants — What Kind of White Dwarfs do They Become?

Published online by Cambridge University Press:  12 April 2016

Icko Iben Jr.*
Affiliation:
University of Illinois

Abstract

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After a brief commentary on the place of “peculiar red giants” in the overall scheme of stellar evolution, an outline is given of the various possibilities for post asymptotic giant branch (AGB) evolution. The behavior of a post-AGB model star is crucially dependent on where in a thermal pulse cycle the mass of the hydrogen-rich envelope is reduced to such an extent that departure from the AGB must follow on a thermal time scale. If departure from the AGB occurs while the model is still burning hydrogen, post-AGB behavior depends on the mass of the helium buffer zone (- zone containing predominantly helium which has been processed through the hydrogen-burning shell following the last thermal pulse on the AGB). If departure occurs at an arbitrary time during the hydrogen-burning phase, then: (1) in - 25% of all cases, the post-AGB model will experience a final helium shell flash, and, in consequence of additional mass loss, may become a non-DA white dwarf; (2) in - 60% of all cases, the model will cease burning hydrogen when the mass in its hydrogen-rich envelope is reduced to ∼ 10-4Mʘ and will evolve into a DA white dwarf; and (3) in - 15% of all cases, the model will experience a final hydrogen shell flash, but the outcome with regard to spectroscopic type is unclear. If departure from the AGB occurs while the model is burning helium, the result is either the same as in option (3) just described, or mass loss during the post-AGB helium-burning phase may turn the star into a non-DA white dwarf.

Type
3. Evolution of Peculiar Red Giant Stars
Copyright
Copyright © Cambridge University Press 1989

References

Fontaine, G., and Wesemael, F. 1987. In The Second Conference on Faint Blue Stars, ed. Davis Philip, A. G., Hayes, D. S., and Liebert, J. W. (L. Davis Press: Schenectady), p. 319.Google Scholar
Fujimoto, M. Y. 1977. Pubi. Astr. Soc. Japan, 29, 331.Google Scholar
Gallino, R. 1988. This Conference.Google Scholar
Härm, R., and Schwarzschild, M. 1975. Ap. J., 200, 324.Google Scholar
Holberg, J. B. 1988. In White Dwarfs, ed. Wegner, G., in press.Google Scholar
Hollowell, D., and Iben, I. Jr. 1988. Ap. J. Lett., 333, 125.Google Scholar
Iben, I. Jr. 1984. Ap. J. 1984. Ap. J., 277, 333.Google Scholar
Iben, I. Jr., and MacDonald, J. 1986. Ap. J., 301, 164.Google Scholar
Iben, I. Jr., and Tutukov, A. V. 1984. Ap. J., 282, 615.Google Scholar
Iben, I. Jr., and Tutukov, A. V. 1986. Ap. J., 311, 742.Google Scholar
Kawaler, S. 1988. Ap. J., 334, 000.Google Scholar
Koester, D. 1987. In The Second Conference on Faint Blue Stars, ed. Davis Philip, A. G., Hayes, D. S., and Liebert, J. W. (Schenectady: L. Davis Press), p. 329.Google Scholar
Lambert, D. L. 1988. This conference.Google Scholar
Lattanzio, J. 1988. This conference.Google Scholar
Liebert, J., Fontaine, G., and Wesemael, F. 1987. Mem. Soc. Astr. Ital., 58, 17.Google Scholar
McClure, R. D. 1988. This conference.Google Scholar
Paczynski, B. 1970. Acta Astron., 20, 47.Google Scholar
Paczynski, B. 1971. Acta Astron., 21, 417.Google Scholar
Renzini, A. 1979. In Stars and Star systems, ed Westerlund, B. E. (Dordrecht: Reidel), p. 155.Google Scholar
Renzini, A. 1983. In Planetary Nebulae, ed. Flower, D. R. (Dordrecht: Reidel), p. 267.Google Scholar
Robinson, E. L. 1988. In White dwarfs. ed Wegner, G., in press.Google Scholar
Schonberner, D. 1979. Astron. Ap., 79, 108.Google Scholar
Schonberner, D. 1986. In Late Stages of Stellar Evolution, ed. Kwok, S. and Pottash, S. R. (Dordrecht: Reidel), p.337.Google Scholar
Shipman, H. 1988. In White Dwarfs, ed. Wegner, G. (Berlin: Springer-Verlag), in press.Google Scholar
Shklovski, I. S. 1956. Astron. Zh., 33, 315.Google Scholar
Wood, P. R., and Faulkner, D. 1986. Ap. J., 307, 659.Google Scholar