Astronomy Colloquium — Evan Henry Anders
December 1 @ 3:30 pm - 4:30 pm
Field: Stars & Planets
Title: Why do massive stars have “inflated” cores?
Abstract: Stars with masses greater than about 1.1 M_sun have turbulent convection in their cores. Standard stellar evolution models fail to reproduce many observations, but models and observations can be brought into agreement by “inflating” the core with excess mixing beyond the boundary of the convection zone. In this colloquium, I will present a review of observations of excess mixing in the cores of massive stars. I will discuss how excess mixing affects stellar evolution and the populations of stars and compact objects which are being characterized by space-based missions like Gaia and ground-based gravitational wave interferometers like LIGO. I will then discuss different forms of convective boundary mixing from a fluid dynamics perspective, talking about three processes which likely occur in stellar interiors. I will discuss one or two sets of simulations which we are using to shed light on this tricky problem in modern stellar astrophysics.
Everyone in Astronomy and Physics departments are welcome. Also accessible via Zoom here.