Photons from the hot photosphere break down atoms and molecules in the surrounding emission nebula.
Large numbers of energetic photons within the core combine to annihilate each other.
Energetic photons within the core catalyze the fusion of iron nuclei with each other, releasing energy.
Individual energetic photons in the very hot core combine with neutrons to release energy in the form of neutrinos and electrons.
Individual energetic photons in the very hot core split iron nuclei and other nuclei down until only protons, neutrons, electrons, and photons remain.