Dredge-up

Dredge-up is a process occurring in stellar astrophysics, particularly in the context of red giant stars. It involves the mixing of materials from the interior of a star to its outer layers, specifically bringing nuclear fusion products from deeper layers, such as helium and heavier elements, to the surface. This process typically happens during specific phases of a star's evolution, notably during the red giant phase when a star expands and cools.