Theoretical and experimental activities on opacities for a good interpretation of seismic stellar probes

TL;DR

This paper reviews theoretical and experimental efforts to improve stellar opacity calculations, which are vital for interpreting seismic data from space missions and understanding stellar structures and compositions.

Contribution

It presents new opacity spectra calculations, compares different models, and reports experimental measurements, highlighting their astrophysical implications.

Findings

Differences in opacity models have significant astrophysical consequences.

Experimental measurements of nickel opacity provide new insights.

Comparisons reveal discrepancies among opacity calculations.

Abstract

Opacity calculations are basic ingredients of stellar modelling. They play a crucial role in the interpretation of acoustic modes detected by SoHO, COROT and KEPLER. In this review we present our activities on both theoretical and experimental sides. We show new calculations of opacity spectra and comparisons between eight groups who produce opacity spectra calculations in the domain where experiments are scheduled. Real differences are noticed with real astrophysical consequences when one extends helioseismology to cluster studies of different compositions. Two cases are considered presently: (1) the solar radiative zone and (2) the beta Cephei envelops. We describe how our experiments are performed and new preliminary results on nickel obtained in the campaign 2010 at LULI 2000 at Polytechnique.