Mass-luminosity relation for FGK main sequence stars: metallicity and age contributions

TL;DR

This study refines the stellar mass-luminosity relation for FGK main sequence stars by incorporating metallicity and age, significantly improving mass estimates and explaining intrinsic dispersion.

Contribution

It introduces a new approach to include age and metallicity in the MLR, enhancing the accuracy of stellar mass estimations for FGK stars.

Findings

Including age and metallicity improves mass estimation accuracy by 5-15%.

The intrinsic dispersion in MLR is partly due to differences in age and chemical composition.

The refined MLR better explains the observed scatter in stellar luminosities.

Abstract

The stellar mass-luminosity relation (MLR) is one of the most famous empirical "laws", discovered in the beginning of the 20th century. MLR is still used to estimate stellar masses for nearby stars, particularly for those that are not binary systems, hence the mass cannot be derived directly from the observations. It's well known that the MLR has a statistical dispersion which cannot be explained exclusively due to the observational errors in luminosity (or mass). It is an intrinsic dispersion caused by the differences in age and chemical composition from star to star. In this work we discuss the impact of age and metallicity on the MLR. Using the recent data on mass, luminosity, metallicity, and age for 26 FGK stars (all members of binary systems, with observational mass-errors <= 3%), including the Sun, we derive the MLR taking into account, separately, mass-luminosity, mass-luminosity-metallicity, and mass-luminosity-metallicity-age. Our results show that the inclusion of age and metallicity in the MLR, for FGK stars, improves the individual mass estimation by 5% to 15%.