Beyond the Main Sequence: Testing the accuracy of stellar masses predicted by the PARSEC evolutionary tracks

TL;DR

This study validates the accuracy of stellar mass estimates for evolved stars using PARSEC evolutionary tracks, showing good agreement with model-independent measurements and supporting their use beyond the main sequence.

Contribution

The paper provides empirical evidence that evolutionary track-based mass estimates for evolved stars are accurate, addressing previous concerns about potential overestimations.

Findings

Mass estimates for evolved stars agree within 2-3% of benchmark measurements.

No significant trends in residuals relative to input parameters.

Validation supports the use of evolutionary tracks for mass determination of evolved stars.

Abstract

Characterizing the physical properties of exoplanets, and understanding their formation and orbital evolution requires precise and accurate knowledge of their host stars. Accurately measuring stellar masses is particularly important because they likely influence planet occurrence and the architectures of planetary systems. Single main-sequence stars typically have masses estimated from evolutionary tracks, which generally provide accurate results due to their extensive empirical calibration. However, the validity of this method for subgiants and giants has been called into question by recent studies, with suggestions that the masses of these evolved stars could have been overestimated. We investigate these concerns using a sample of 59 benchmark evolved stars with model-independent masses (from binary systems or asteroseismology) obtained from the literature. We find very good agreement between these benchmark masses and the ones estimated using evolutionary tracks. The average fractional difference in the mass interval $\sim$0.7 - 4.5 M$_{\odot}$, is consistent with zero (-1.30 $\pm$ 2.42%), with no significant trends in the residuals relative to the input parameters. A good agreement between model-dependent and -independent radii (-4.81 $\pm$ 1.32%) and surface gravities (0.71 $\pm$ 0.51%) is also found. The consistency between independently determined ages for members of binary systems adds further support for the accuracy of the method employed to derive the stellar masses. Taken together, our results indicate that determination of masses of evolved stars using grids of evolutionary tracks is not significantly affected by systematic errors, and is thus valid for estimating the masses of isolated stars beyond the main sequence.