Standing on the shoulders of giants: New mass and distance estimates for Betelgeuse through combined evolutionary, asteroseismic, and hydrodynamic simulations with MESA
Meridith Joyce, Shing-Chi Leung, L. Molnár, Michael Ireland, Chiaki Kobayashi, K. Nomoto
Abstract
We conduct a rigorous examination of the nearby red supergiant Betelgeuse by drawing on the synthesis of new observational data and three different modeling techniques. Our observational results include the release of new, processed photometric measurements collected with the space-based Solar Mass Ejection Imager instrument prior to Betelgeuse’s recent, unprecedented dimming event, and the detection of a new pulsation mode in the star. Our theoretical predictions include self-consistent results from multi-timescale evolutionary, oscillatory, and hydrodynamic simulations conducted with the Modules for Experiments in Stellar Astrophysics (MESA) software suite. Significant outcomes of our modeling efforts include a precise prediction for the star's radius; in concert with additional constraints, this allows for the derivation of new estimate for its distance that is independent of its trigonometric parallax. Seismic results from both perturbed hydrostatic and evolving hydrodynamic simulations constrain the frequencies and underlying physics of Betelgeuse’s dominant periodicities in new ways, allowing us to determine conclusively, and for the first time, the driving mechanisms for Betelgeuse's most prominent oscillation modes.