Description:

Abstract: Convective motions in stars extend beyond the boundary of a convection zone, leading to additional mixing in the radiative zone. This can have important consequences for stellar evolution, including larger core masses and main sequence lifetimes of massive stars. These effects propagate throughout the lives of massive stars, and have important implications for the formation of compact objects. I will review some previous work and ideas around radiative-convective interfaces. In particular, I will describe convective overshoot which causes chemical mixing, and convective penetration which causes thermodynamic mixing. I will present a series of simulations exhibiting significant convective penetration, and present mechanistic and parametric descriptions of the phenomenon. These can be implemented in stellar evolution models, and used to compare to stellar observations.

Speaker: Daniel Lecoanet, Northwestern University