Select all that apply. After the sun leaves the main sequence, its helium core will contract until electron degeneracy pressure sets in. Consequently, when helium burning begins:
A. The core will expand like a gas, causing the core density to decrease. This will cause the helium burn rate to slow to a steady value.
B. The core will behave like a liquid and not expand. Consequently, the core will grow hotter, causing the helium burn rate to increase, causing the core to grow hotter, etc.
C. Electron degeneracy pressure will be maintained until the core grows hot enough for it to behave like a gas again.