Radiative properties of stellar plasmas and open challenges

TL;DR

This paper reviews the importance of radiative properties of stellar plasmas, especially monochromatic opacity, in stellar evolution and pulsation, highlighting current theoretical estimates and experimental challenges.

Contribution

It provides a comprehensive review of radiative properties in stellar envelopes, focusing on opacity estimates and the experimental challenges to validate them.

Findings

Dispersion among eight theoretical opacity estimates

Significant experimental challenges identified

Implications for stellar modeling and evolution

Abstract

The lifetime of solar-like stars, the envelope structure of more massive stars, and stellar acoustic frequencies largely depend on the radiative properties of the stellar plasma. Up to now, these complex quantities have been estimated only theoretically. The development of the powerful tools of helio- and astero- seismology has made it possible to gain insights on the interiors of stars. Consequently, increased emphasis is now placed on knowledge of the monochromatic opacity coefficients. Here we review how these radiative properties play a role, and where they are most important. We then concentrate specifically on the envelopes of $\beta$ Cephei variable stars. We discuss the dispersion of eight different theoretical estimates of the monochromatic opacity spectrum and the challenges we need to face to check these calculations experimentally.