Abstract
We show that in evolved stars, even at relatively low surfaceamplitudes, nonradial modes become strongly nonlinear in thehydrogen shell source, where the Brunt-Väisälä frequency hasits absolute maximum. The measure of nonlinearity is the productof horizontal displacement times the radial wavenumber, \(\left| {\xi _H k_r } \right|\). It becomes large already in evolved δ-Scuti stars.This nonlinearity presents a major problem for interpretations ofamplitude modulation in RR Lyrae stars in terms of nonradial modeexcitation.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Breger, M. and Pamyatnykh, A.A.: 2002: in: C. Aerts, T.R. Bedding and J. Christensen-Dalsgaard (eds.), Radial and Nonradial Pulsations as Probes of Stellar Physics, ASP Conf. Ser. 259, 388.
Kovács, G.: 2002: in: C. Aerts, T.R. Bedding and J. Christensen-Dalsgaard (eds.), Radial and Nonradial Pulsations as Probes of Stellar Physics, ASP Conf. Ser. 259, 396.
Kumar, P. and Goodman, J.: 1996, ApJ 466, 946.
Nowakowski, R.M. and Dziembowski, W.A.: 2001, Acta Astron. 51, 5.
Shibahashi, H.: 2000, in: L. Szabados and D. Kurtz (eds.), The Impact of Large Scale Surveys on Pulsating Star Research, ASP Conf. Ser. 203, 299.
Van Hoolst, T.: 1994, A&A 286, 879.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Nowakowski, R.M., Dziembowski, W.A. Nonlinearity of Nonradial Modes in Evolved Stars. Astrophysics and Space Science 284, 273–276 (2003). https://doi.org/10.1023/A:1023260223343
Issue Date:
DOI: https://doi.org/10.1023/A:1023260223343