The Role of Opacities in Stellar Pulsation

TL;DR

This paper investigates how increased opacities, especially iron opacities, influence stellar pulsation models for Cepheids, RR Lyraes, and B-star pulsators, revealing notable effects in light curves and period ranges.

Contribution

It introduces the impact of augmented opacities on pulsation models, addressing recent findings of underestimated iron opacities and their effects on stellar pulsation predictions.

Findings

Augmented opacities affect Cepheid light curves around $ ext{log} P ext{≈} 1$

Significant effects observed in B-star pulsation models

Opacity increases influence pulsation periods and amplitudes

Abstract

We examine the role of opacities in stellar pulsation with reference to Cepheids and RR Lyraes, and examine the effect of augmented opacities on the theoretical pulsation light curves in key temperature ranges. The temperature ranges are provided by recent experimental and theoretical work that have suggested that the iron opacities have been considerably underestimated. For Cepheids, we find that the augmented opacities have noticeable effects in certain period ranges (around $\log P \approx 1$) even though there is a degeneracy with mixing length. We also find significant effects in theoretical models of B-star pulsators.