Description
Convective motions in stars extend beyond the boundary of a convection zone, leading to additional mixing in the radiative zone. This occurs in both solar-type stars, and more massive stars with convective cores. This mixing is especially important for massive stars, leading to larger core masses and main sequence lifetimes of massive stars. In this talk, I will review some previous 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. When implemented in stellar evolution models, these effects compare favorably to asteroseismic observations.
