Complex asteroseismology of the hybrid B-type pulsator $\gamma$ Pegasi: a test of stellar opacities

TL;DR

This study uses complex asteroseismology of the hybrid B-type pulsator $ ext{γ}$ Pegasi to test stellar opacities, finding both OPAL and OP opacity tables equally suitable for modeling its pulsation modes.

Contribution

It introduces a comprehensive seismic modeling approach that incorporates the complex nonadiabatic parameter $f$ to test stellar opacities and metallicity in $ ext{γ}$ Pegasi.

Findings

Both OPAL and OP opacity tables fit the observed pulsation data.

Seismic models successfully reproduce key pulsation frequencies.

The method provides a new way to test stellar opacities using pulsation data.

Abstract

Using the updated oscillation spectrum of $\gamma$ Pegasi, we construct a set of seismic models which reproduce two pulsational frequencies corresponding to the $\ell=0$, p$_1$ and $\ell=1$, g$_1$ modes. Then, we single out models which reproduce other well identified modes. Finally, we extend our seismic modelling by a requirement of fitting also values of the complex, nonadiabatic parameter $f$ associated to each mode frequency. Such complex asteroseismology of the B-type pulsators provides a unique test of stellar metallicity and opacities. In contrast to our previous studies, results for $\gamma$ Peg indicate that both opacity tables, OPAL and OP, are equally preferred.