vansig wrote:
I thought that the Sun uses the CNO cycle?
— http://en.wikipedia.org/wiki/CNO_cycle
No, our sun is too small for the CNO cycle to be a significant contribution. As it says in the wiki, a star needs to be at around 1.3 times as massive as the sun for its core to be hot enough to support this cycle.
The size/temperature dependence is shown here: http://csep10.phys.utk.edu/astr162/lect/energy/cno-pp.html
