Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-17T15:20:41.646Z Has data issue: false hasContentIssue false

A New Asymptotic Treatment of g-modes of a Star

Published online by Cambridge University Press:  12 April 2016

P. Smeyers
Affiliation:
Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200B, 3001 Heverlee, Belgium
T. Van Hoolst
Affiliation:
Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200B, 3001 Heverlee, Belgium
I. De Boeck
Affiliation:
Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200B, 3001 Heverlee, Belgium
L. Decock
Affiliation:
Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200B, 3001 Heverlee, Belgium

Extract

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.

An asymptotic representation of low-frequency, linear, isentropic g-modes of a star is developed without the usual neglect of the Eulerian perturbation of the gravitational potential. Our asymptotic representation is based on the use of asymptotic expansions adequate for solutions of singular perturbation problems (see, e.g., Kevorkian & Cole 1981).

Linear, isentropic oscillation modes with frequency different from zero are governed by a fourth-order system of linear, homogeneous differential equations in the radial parts of the radial displacement ξ(r) and the divergence α(r). These equations take the form

The symbols have their usual meaning. N2 is the square of the frequency of Brunt-Väisälä. The functions K1 (r), K2 (r), K3 (r), K4 (r), depend on the equilibrium model, e.g.,

We introduce the small expansion parameter

and assume, for the sake of simplification, N2 to be positive everywhere in the star so that the star is everywhere convectively stable.

Type
Part 2. Poster Papers
Copyright
Copyright © Astronomical Society of the Pacific 1995

References

Kevorkian, J., & Cole, J.D. 1981, Perturbation Methods in Applied Mathematics, Springer, New-York CrossRefGoogle Scholar
Smeyers, P., & Tassoul, M. 1987, ApJS, 65, 429 CrossRefGoogle Scholar