Semiconvective mixing in low-mass stars

Abstract

Mixing processes such as convection, overshooting and rotational mixing have long been known to affect the evolutionary properties of low-mass stars. While modeling a 1.2 Msun star, we encountered a semiconvective region outside the fully convective core, reminiscent of the well-known situation for massive stars. In this study we focus on low-mass stars presenting convective cores and, by applying different prescriptions for the determination of the convective boundaries and using different mixing descriptions for the dynamical processes in the core, we look for the effects of semiconvective mixing in the interior structure of the stars and its observable quantities. With this purpose, we have constructed different sets of evolutionary models using a stellar evolution code (GARSTEC), and analyzed the models looking for imprints of these processes.