Wednesday 17 Dec 2014: Seminar: Convective overshooting in stellar interiors
Robert Andrassy - MPA, Garching
Physics, 4th floor 14:00-15:00
Hydrodynamic mixing processes are modelled very crudely in stellar-evolution codes, although they have a significant impact on stellar evolution and nucleosynthesis. There is ample observational evidence that some form of mixing extends beyond the formal boundaries of stellar convection zones. This "overshoot" can be provided by several physical mechanisms, depending on the type of convection zone in question. I will focus on two of them, which have been paid little attention to so far: the "convective settling" process could explain the lithium depletion observed in low mass stars, while the "differential heating" process could provide some mixing at the boundaries of stellar convective cores and shells.