What quantum mechanical effect supports the dense helium core in low-to-intermediate mass stars before helium fusion begins?

Answer

Electron degeneracy pressure

The dense, inert helium core is supported by electron degeneracy pressure, a quantum mechanical effect that prevents further compression even as the temperature rises, until helium fusion finally ignites.

What quantum mechanical effect supports the dense helium core in low-to-intermediate mass stars before helium fusion begins?
astronomystarstellar evolutionmain-sequencered giant