TY - JOUR
T1 - Standing on the Shoulders of Giants
T2 - New Mass and Distance Estimates for Betelgeuse through Combined Evolutionary, Asteroseismic, and Hydrodynamic Simulations with MESA
AU - Joyce, Meridith
AU - Leung, Shing Chi
AU - Molnár, László
AU - Ireland, Michael
AU - Kobayashi, Chiaki
AU - Nomoto, Ken'ichi
N1 - Publisher Copyright:
© 2020. The American Astronomical Society. All rights reserved.
PY - 2020/10/10
Y1 - 2020/10/10
N2 - 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. We detect the first radial overtone in the photometric data and report a period of 185 ± 13.5 days. Our theoretical predictions include self-consistent results from multi-timescale evolutionary, oscillatory, and hydrodynamic simulations conducted with the Modules for Experiments in Stellar Astrophysics software suite. Significant outcomes of our modeling efforts include a precise prediction for the star's radius: In concert with additional constraints, this allows us to derive a new, independent distance estimate of pc and a parallax of mas, in good agreement with Hipparcos but less so with recent radio measurements. Seismic results from both perturbed hydrostatic and evolving hydrodynamic simulations constrain the period and driving mechanisms of Betelgeuse's dominant periodicities in new ways. Our analyses converge to the conclusion that Betelgeuse's 400 day period is the result of pulsation in the fundamental mode, driven by the κ-mechanism. Grid-based hydrodynamic modeling reveals that the behavior of the oscillating envelope is mass-dependent, and likewise suggests that the nonlinear pulsation excitation time could serve as a mass constraint. Our results place Orionis definitively in the early core helium-burning phase of the red supergiant branch. We report a present-day mass of 16.5-19 M-slightly lower than typical literature values.
AB - 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. We detect the first radial overtone in the photometric data and report a period of 185 ± 13.5 days. Our theoretical predictions include self-consistent results from multi-timescale evolutionary, oscillatory, and hydrodynamic simulations conducted with the Modules for Experiments in Stellar Astrophysics software suite. Significant outcomes of our modeling efforts include a precise prediction for the star's radius: In concert with additional constraints, this allows us to derive a new, independent distance estimate of pc and a parallax of mas, in good agreement with Hipparcos but less so with recent radio measurements. Seismic results from both perturbed hydrostatic and evolving hydrodynamic simulations constrain the period and driving mechanisms of Betelgeuse's dominant periodicities in new ways. Our analyses converge to the conclusion that Betelgeuse's 400 day period is the result of pulsation in the fundamental mode, driven by the κ-mechanism. Grid-based hydrodynamic modeling reveals that the behavior of the oscillating envelope is mass-dependent, and likewise suggests that the nonlinear pulsation excitation time could serve as a mass constraint. Our results place Orionis definitively in the early core helium-burning phase of the red supergiant branch. We report a present-day mass of 16.5-19 M-slightly lower than typical literature values.
UR - http://www.scopus.com/inward/record.url?scp=85094573612&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/abb8db
DO - 10.3847/1538-4357/abb8db
M3 - Article
SN - 0004-637X
VL - 902
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 63
ER -