Three Dimensional Radiation Hydrodynamic Simulations of Massive Star Envelopes

Understand

(Abridged) Stars more massive than $20-30M_{\odot}$ are so luminous that the radiation force on the cooler, more opaque outer layers can balance or exceed the force of gravity.

• These near or super-Eddington outer envelopes represent a long standing challenge for calculating the evolution of massive stars in one dimension, a situation that limits our understanding of the stellar progenitors of some of the most exciting and energetic explosions in the universe.
• In particular, the proximity to the Eddington limit has been the suspected cause for the variability, large mass loss rate and giant eruptions of an enigmatic class of massive stars: the luminous blue variables (LBVs).
• When in quiescence, LBVs are usually found on the hot ($T_{eff} \approx 2 - 4 \times 10^4$ K) S Dor instability strip.