Hostname: page-component-7c8c6479df-995ml Total loading time: 0 Render date: 2024-03-28T14:01:57.642Z Has data issue: false hasContentIssue false

Interactions between Rotation and Pulsation

Published online by Cambridge University Press:  26 May 2016

Rich Townsend*
Affiliation:
Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, UK

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

In this contribution, I will examine the interaction between stellar rotation and pulsation. I begin with a brief review of the non-rotating case, emphasizing the character of pulsations as azimuthally-propagating waves. I then go on to discuss how these waves are modified under the influence of the centrifugal and Coriolis forces. Through simple arguments, I outline the conditions under which each force can become significant in determining the wave dynamics. Particular attention is paid to the Coriolis force, since it is responsible for the formation of a waveguide, which confines the pulsation to a narrow band centered on the stellar equator. Using the example of a prograde sectoral pulsation mode, I explain the basic physical principles underlying this trapping.

The Coriolis force is also responsible for the existence of Rossby waves, which are not found in non-rotating stars. I demonstrate how these waves may be understood in terms of a conservation law for angular momentum, and review their most important characteristics. I then examine how rotation modifies the frequencies of pulsation, and explain how observations of such modifications can provide information regarding a star's rotation rate. To conclude, I focus on the converse of the pulsation-rotation interaction: how the transport of angular momentum by pulsation might be important in determining the evolution of a star's rotation profile.

Type
Session 3 Rotation, Solar and Stellar Physics
Copyright
Copyright © Astronomical Society of the Pacific 2004 

References

Ando, H. 1983, PASJ 35, 343 Google Scholar
Balona, L. A. 1994, MNRAS 267, 1060 CrossRefGoogle Scholar
Bildsten, L., Ushomirsky, G., Cutler, C. 1996, ApJ 460, 827 CrossRefGoogle Scholar
Dziembowski, W. A., Pamyatnykh, A. A. 1993, MNRAS 262, 204 CrossRefGoogle Scholar
Gill, A. E. 1982, Atmosphere-Ocean Dynamics. Academic Press, London Google Scholar
Ledoux, P. 1951, ApJ 114, 373 CrossRefGoogle Scholar
Lee, U., Baraffe, I. 1995, A&A 301, 419 Google Scholar
Lee, U., Saio, H. 1990, ApJ 349, 570 CrossRefGoogle Scholar
Matsuno, T. 1966, J. Meteor. Soc. Japan, 44, 25 CrossRefGoogle Scholar
Saio, H. 1982, ApJ 256, 717 CrossRefGoogle Scholar
Soufi, F., Goupil, M. J., Dziembowski, W. A. 1998, A&A 334, 911 Google Scholar
Townsend, R. H. D. 2003, MNRAS in press Google Scholar
Unno, W., Osaki, Y., Ando, H., Saio, H., Shibahashi, H. 1989, Nonradial Oscillations of Stars, 2nd edn. University of Tokyo Press, Tokyo Google Scholar