Double bow shocks around young, runaway red supergiants: application to Betelgeuse

摘要: A significant fraction of massive stars are moving supersonically through the interstellar medium (ISM), either due to disruption a binary system or ejection from their parent star cluster. The interaction wind with ISM produces bow shock. In late evolutionary stages these may undergo rapid transitions red blue and vice versa on Hertzsprung-Russell diagram, accompanying changes stellar winds shocks. Recent 3D simulations shock produced by nearby runaway supergiant (RSG) Betelgeuse, under assumption constant wind, indicate that is very young (<30000 years old), hence Betelgeuse have only recently become RSG. To test this possibility, we calculated evolution models for single which match observed properties in RSG phase. resulting evolving incorporated into 2D hydrodynamic model (BSG) as it undergoes transition near end its life. We find collapsing BSG bubble induces shock-shaped inner shell around resembles Betelgeuse's shock, has similar mass. Surrounding larger-scale retreating generated now defunct wind's ISM. suggest outer could explain bar feature located (at least projection) just front