Simulation of an evolved, massive star, where carbon-shell material in an outer envelope is ingested into a convective, oxygen-burning interior. Rendering shows a thin slice through the computational box of the "fractional volume" of carbon, which is initially confined to a thin shell at the outskirts of the star (red). The structure reveals a flow field dominated by a few, large-scale convective zones. As a result, the carbon is mixed into the interior of the star, and its relative abundance decreases (yellow to green to blue). The inhomogeneous distribution of 12C will result in an asymmetric distribution of the nuclear energy generation rate via the 12C + 12C reaction.
Methods: MESA ICs; PPMstar code