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roAp Stars through Theorists' Eyes - Excitation Mechanism

Published online by Cambridge University Press:  08 February 2017

Alfred Gautschy  and
Hideyuki Saio
Alfred Gautschy
Affiliation:
Astronomisches Institut der Universität Basel, Venusstrasse 7, CE-4102, Binningen, Switzerland
Hideyuki Saio
Affiliation:
Astronomical Institute, School of Sciences, Tohoku University, Sendai 980-77, Japan

Abstract

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This exposition focuses on the still elusive excitation mechanism of the rapid oscillations in some Ap stars. We visit the domain of overstable magnetic convection which was conjectured as the origin of the observed high radial-order p modes. Mostly we dwell, however, on the classical k-mechanism. In roAp stars, the zone of partial hydrogen ionization is driving rather effectively. Furthermore, we argue that an atmospheric temperature inversion supports the κ-mechanism driving by preventing oscillation energy from leaking into the atmosphere.

Type
V. Asteroseismology I
Information
Symposium - International Astronomical Union , Volume 185: New Eyes to See Inside the Sun and Stars , 1998 , pp. 277 - 284
Copyright
Copyright © Kluwer 1998 

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