Data: 14.11.2023

Jadwiga Daszynska-Daszkiewicz (Wroclaw University)

A need to revise stellar opacities from seismology of delta Sct and SX Phe stars

Streszczenie:
So far asteroseismology provides the most stringent constraints on the theory of stellar structure and evolution. It also offers a test of microphysics data, in particular stellar opacities, which are among the major and still uncertain components of modern astrophysics.
I will present the results of seismic modelling of a few AF-type pulsators adopting three opacity databases that are widely used in evolutionary modelling, i.e., OPAL, OP and OPLIB. The aim is to find the models that fit the observed frequencies of pulsational modes and have effective temperature and luminosity consistent with the observed values. Using the Bayesian analysis based on Monte Carlo simulations, we obtain that only the seismic models computed with one of the three opacity tables are caught within the observed error box in the Hertzsprung-Russell diagram. Seismic models computed with the other two opacity tables are much cooler and less luminous. A similar effect can also occur for seismic models of classical Cepheids or RR Lyr stars.