Input from opacity data in computation of pulsation instability

TL;DR

This paper investigates how different opacity data and chemical compositions influence the pulsation instability regions of various variable stars driven by the $$-mechanism, highlighting the importance of opacity in stellar pulsation modeling.

Contribution

It provides a comparative analysis of the effects of OP and OPAL opacity tables and chemical compositions on the pulsation instability domains of A and B type stars.

Findings

Opacity data significantly affect the predicted instability domains.

Chemical composition variations alter pulsation driving regions.

Opacity impacts non-$$-mechanism pulsators like $$ Doradus and solar-like stars.

Abstract

Several types of variable stars are found along the HR diagram whose pulsations are driven by the $\kappa$-mechanism. Given their nature, the precise ($T_{\rm eff}-L$) domain where these pulsators are located is highly dependent on the value of opacity and on its variation inside the star. We analyze the sensitivity of opacity driven pulsators of spectral-type A and B ($\delta$ Scuti, $\beta$ Cephei and SPB stars) to the opacity tables (OP/OPAL) and to the chemical composition of the stellar matter. We also briefly discuss the effect of opacity on pulsators whose oscillations are not driven by the $\kappa$-mechanism, such as $\gamma$ Doradus and solar-like stars.