Computing Solar Absolute Fluxes

TL;DR

This paper discusses the challenges and progress in accurately computing absolute solar fluxes using model atmospheres, highlighting issues with data consistency and solar composition uncertainties.

Contribution

It presents updated methods for calculating solar absolute fluxes and addresses the impact of solar composition uncertainties on these calculations.

Findings

Improved models for solar flux predictions

Identification of composition uncertainties as a major error source

Progress in aligning models with observed irradiances

Abstract

Computed color indices and spectral shapes for individual stars are routinely compared with observations for essentially all spectral types, but absolute fluxes are rarely tested. We can confront observed irradiances with the predictions from model atmospheres for a few stars with accurate angular diameter measurements, notably the Sun. Previous calculations have been hampered by inconsistencies and the use of outdated atomic data and abundances. I provide here a progress report on our current efforts to compute absolute fluxes for solar model photospheres. Uncertainties in the solar composition constitute a significant source of error in computing solar radiative fluxes.