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Secular Instabilities

Published online by Cambridge University Press:  30 March 2016

B. Paczyński

Extract

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The relation between a linear series and thermal (i.e. secular) stability of stellar models is discussed. Models of accreting degenerate dwarfs are considered as an example of transition from instability to stability. This transition occurs while the accretion rate increases. Such models are relevant for novae and symbiotic stars.

I shall limit this presentation to the secular i.e. thermal instabilities of stellar models in the hydrostatic and thermal equilibria. The time dependence of a small perturbation of an equilibrium model is assumed to be exponential, but the eigenvalues do not have to be real. In general they are complex. That means that thermal instability, if present, may either lead to an exponential growth of a perturbation, or may lead to oscillations with a growing amplitude. The complex nature of the eigenvalues makes a search for them difficult and no general prescription is available for a search to be complete and successful. However, a search for real eigenvalues is much easier. Some information about the presence of purely exponential modes may be achieved even without searching for them by means of calculating a linear series of stellar models. I shall describe this concept in this communication.

Type
Joint Discussion
Information
Highlights of Astronomy , Volume 5: Highlights of Astronomy. As presented at the XVIIth General Assembly of the IAU, 1979 , 1980 , pp. 437 - 439
Copyright
Copyright © Cambridge University Press 1980

References

Gabriel, M., and Ledoux, P., 1967. Ann. Astrophys., 30, 975.Google Scholar
Gabriel, M., and Noels, A., 1973. Astron. Astrophys., 5, 313.Google Scholar
Gabriel, M., and Noels-Grotsch, A., 1968. Ann. Astrophys., 31, 167.Google Scholar
Gabriel, M., Refsdal, S., and Ritter, H., 1974. Astron. Astrophys., 32, 217.Google Scholar
Gallagher, J.S., and Starrfield, S., 1978. Ann. Review Astron. Astrophys., 16, 171.Google Scholar
Hansen, C.J., 1978. Ann. Review Astron. Astrophys., 16, 15.CrossRefGoogle Scholar
Kozłowski, M., and Paczynski, B., 1973. Acta Astron., 23, 65.Google Scholar
Kozłowski, M., and Paczyński, B., 1975. Acta Astron., 25, 321.Google Scholar
Kozłowski, M., Paczyński, B., and Popova, K., 1973. Acta Astron., 23, 263.Google Scholar
Lauterborn, D., and Siquig, R.A., 1974. Astron. Astrophys., 30, 385.Google Scholar
Paczyński, B., 1972. Acta Astron., 22, 163.Google Scholar
Paczyński, B., 1973. Astron. Astrophys., 26, 291.Google Scholar
Paczyński, B., and Kozłowski, M., 1972. Acta Astron., 22, 315.Google Scholar
Paczyński, B., and Różyczka, M., 1977. Acta Astron., 27, 213.Google Scholar
Paczyński, B., and Rudak, B., 1979. Astron. Astrophys., in publication.Google Scholar
Paczyński, B., Żytkow, A., 1978. Astrophys. J., 222, 604.CrossRefGoogle Scholar
Sienkiewicz, R., 1975. Astron. Astrophys., 45, 411.Google Scholar
Sienkiewicz, R., 1979. submitted to Astron. Astrophys.Google Scholar
Sion, E.M., Acierno, M.J., and Tomczyk, S., 1979. Astrophys. J., 230, 832 CrossRefGoogle Scholar
Sion, E.M., Acierno, M.J., and Turnshek, U.A., 1978, Astrophys. J., 220, 636.CrossRefGoogle Scholar