Thursday

I will describe a new multi-dimensional framework for the study of hydrodynamical processes in stellar interiors. The development is motivated by the current reliance on one-dimensional stellar evolution calculations in which complex physical processes, such as convection, rotation, or accretion, are described by simplified, phenomenological approaches. The predictive power of these methods, however, is severely hindered by their dependence on free parameters. In order to redress this situation, and to meet the challenges posed by the unprecedented quality of data provided by modern observational efforts, we developed the MUlti-dimensional Stellar Implicit Code (MUSIC).

By solving the fully compressible equations of hydrodynamics, in three-dimensional spherical geometry, MUSIC is able to study key snapshots of stellar evolution in detail. I will summarise the core algorithms of MUSIC, as well as the numerical methods used to overcome the difficulties caused by the extreme variations of time and length scales present in stellar interiors. Recent developments of MUSIC, including the coupling to the widely used stellar evolution code, MESA, will be discussed, as well as conclusions from a recent benchmarking study. Finally, I will summarise on-going applications of the code.