RR Lyrae Pulsation Theory

TL;DR

This paper reviews the development and application of nonlinear pulsation models for RR Lyrae stars, emphasizing their role in understanding stellar properties and distances, and discusses recent advances and ongoing debates.

Contribution

It presents recent results from nonlinear pulsation models including convection, highlighting their success in reproducing observables and constraining stellar parameters.

Findings

Models accurately reproduce observed pulsation properties

Relations established for stellar parameter estimation

Discussion of unresolved issues in pulsation modeling

Abstract

RR Lyrae stars play an important role as distance indicators and stellar population tracers. In this context the construction of accurate pulsation models is crucial to understand the observed properties and to constrain the intrinsic stellar parameters of these pulsators. The physical mechanism driving pulsation in RR Lyrae stars has been known since the middle of the 20th century and many efforts have been performed during the last few decades in the construction of more and more refined pulsation models. In particular, nonlinear pulsation models including a nonlocal time-dependent treatment of convection, such as the ones originally developed in Los Alamos in the seventies, allow us to reproduce all the relevant observables of radial pulsation and to establish accurate relations and methods to constrain the intrinsic stellar properties and the distance of these variables. The most recent results on RR Lyrae pulsation obtained through these kinds of models will be presented and a few still debated problems will be discussed.