Turbulent Convection in Stellar Cores

Abstract

Convection in stellar cores hosts a wide range of fluid dynamical phenomena. Characterized by high Reynolds and Peclet numbers, the convection is rotationally constrained with low Rossby numbers and has very low Prandtl and Mach numbers. This review describes the main properties of this turbulent convection, as well as how associated fluid processes affect our broader understanding of stars. Numerical simulations have given new insights into the dynamics of convection in stellar cores. As the convection has very high Rayleigh numbers and is internally heated and internally cooled, it appears to be in the ultimate, or diffusion free, regime. The convection drives a magnetic dynamo, leads to mixing at the boundary of the convection zone, and generates internal waves that propagate into the stably stratified stellar envelope. While we are beginning to understand some of these aspects of stellar convection, many properties of stellar cores remain a mystery, and new efforts are required to determine how these fluid processes affect stellar evolution.