Convective cores and carbon ignition in intermediate-mass stars

We find that in intermediate-mass stars, convective overshooting during central He burning is responsible for the overgrowth of the convective core. As a consequence, the upper mass limit for stars developing a degenerate C-O core is strongly reduced. It is shown that when such an effect is taken into account, some previous disagreements between theory and observation are spontaneously solved. Finally, we briefly discuss the implications convective overshooting has on supernovae triggered by electron capture