Theory of Stellar Oscillations

TL;DR

This paper reviews the fundamental theory of stellar pulsations, focusing on adiabatic oscillations in stars, including the types of modes and their physical properties, to support research in asteroseismology.

Contribution

It provides a comprehensive overview of the basic theoretical framework of stellar oscillations, emphasizing mode properties and their relevance to asteroseismic data analysis.

Findings

Analysis of p-, g-, and f-modes in stellar oscillations

Discussion of propagation cavities for different modes

Foundational equations for stellar pulsation theory

Abstract

In recent years, astronomers have witnessed major progresses in the field of stellar physics. This was made possible thanks to the combination of a solid theoretical understanding of the phenomena of stellar pulsations and the availability of a tremendous amount of exquisite space-based asteroseismic data. In this context, this chapter reviews the basic theory of stellar pulsations, considering small, adiabatic perturbations to a static, spherically symmetric equilibrium. It starts with a brief discussion of the solar oscillation spectrum, followed by the setting of the theoretical problem, including the presentation of the equations of hydrodynamics, their perturbation, and a discussion of the functional form of the solutions. Emphasis is put on the physical properties of the different types of modes, in particular acoustic (p-) and gravity (g-) modes and their propagation cavities. The surface (f-) mode solutions are also discussed. While not attempting to be comprehensive, it is hoped that the summary presented in this chapter addresses the most important theoretical aspects that are required for a solid start in stellar pulsations research.