Both observations and direct numerical simulations are discordant withpredictions of conventional stellar evolution codes for the latest stages of amassive star's life prior to core collapse. We suggest that the problem lies inthe treatment of turbulent convection in these codes, which ignores finiteamplitude fluctuations in velocity and temperature, and their nonlinearinteraction with nuclear burning. The hydrodynamic instabilities that may ariseprompt us to discuss a number of far-reaching implications for the fates ofmassive stars. In particular, we explore connections to enhanced presupernovamass loss, unsteady nuclear burning and consequent eruptions, swelling of thestellar radius that may trigger violent interactions with a companion star, andpotential modifications to the core structure that could dramatically impactcalculations of the core-collapse mechanism itself. These modifications may beof fundamental importance to the interpretation of measured isotopic anomaliesin meteorites, changing the predictions of both mixing and detailednucleosynthesis, and of young core-collapse supernova remnants. They may alsomake possible the development of an early warning system for the detection ofimpending core collapse.
展开▼
