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Theoretical Results on WR Instabilities

Published online by Cambridge University Press:  03 August 2017

André Maeder
Affiliation:
Geneva Observatory CH-1290 Sauverny, Switzerland
Gérard Schaller
Affiliation:
Geneva Observatory CH-1290 Sauverny, Switzerland

Abstract

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The instabilities of WR stars are discussed in the framework of both the quasi-adiabatic and non-adiabatic methods. We show that a very careful treatment of stellar opacities is necessary. Both methods show that WR stars, with little or no H left, are vibrationally unstable in the fundamental radial mode due to the ε-mechanism, confirming earlier results by Maeder (1985). Thus, from the point of view of stability, WR stars are fundametally different from O stars. Our new analysis also supports our previous view that WR stars evolve, keeping at the edge of vibrational instability.

Type
Session III. Intrinsic Variability
Copyright
Copyright © Kluwer 1991 

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