The growth of helium-burning cores
Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748
2 Monash Center for Astrophysics, Monash University, Clayton VIC 3800, Australia
Received: 11 August 2015
Accepted: 1 September 2015
Helium burning in the convective cores of horizontal branch and red clump stars appears to involve a process of “ingestion” of unburnt helium into the core, the physics of which has not been clearly identified yet. I show here that a limiting factor controlling the growth is the buoyancy of helium entering the denser C+O core. It yields a growth rate that scales directly with the convective luminosity of the core and agrees with constraints on core size from current asteroseismology.
Key words: stars: evolution / convection / stars: horizontal-branch
© ESO, 2015