\`A Propos Nonlinear Pulsations of R CrB Variables

TL;DR

This study uses stellar evolution models to explore pulsations in R CrB variables, revealing that these stars exhibit strange mode pulsations consistent with observed periods.

Contribution

It demonstrates that helium-star models can reproduce pulsational instabilities matching observed R CrB variable periods, suggesting strange modes are involved.

Findings

Pulsation periods match observed R CrB variables.

Pulsations are likely strange modes.

Helium-star models can simulate R CrB pulsations.

Abstract

Helium-star models were dynamically evolved into the region of the HR Diagram where R CrB variables are found. The MESA stellar evolution code was able to pick up pulsational instabilities with cycle lengths that are compatible with the periods observed in pulsating R CrB variables. The properties of the computed pulsations hint at their being strange modes.