Revised Best Estimates for the Age and Mass of the Methuselah Star HD 140283 Using MESA and Interferometry and Implications for 1D Convection

Abstract In light of recently revised observational measurements of the radius and spectroscopic parameters of the extremely old and metal-poor Gaia benchmark star HD 140283—also known as the Methuselah star due to prior suggestions that its age is in tension with the age of the universe—we present new, best estimates for the star’s mass and age from stellar modeling. These are derived using 1D stellar evolutionary tracks computed with MESA and the most up-to-date measurements from CHARA interferometry. Excluding modeling variance from the uncertainties, we report a mass of 0.809 ± 0.001 M ⊙ and an age of 12.01 ± 0.05 Gyr (1 σ ). When dominant sources of modeling uncertainty are taken into account, we report 0.81 ± 0.05 M ⊙ and 12 ± 0.5 Gyr, respectively. These results are consistent with recent literature, and the best-fitting age is not in conflict with the currently accepted age of the universe (13.5 Gyr).