The Origin, Composition, and Energy Source for the Sun
  Heterogeneous supernova debris formed the solar system. Cores of inner planets formed in the central iron rich region. The Sun formed on the collapsed supernova core. Lighter elements and the lighter isotopes of each element are enriched at the solar surface. The most abundant nuclide in the Sun is Iron 56, the decay product of doubly magic Nickel 56. Doubly magic Oxygen 16 is next most abundant. The least abundant elements, Li, Be, and B, have loosely bound nucleons. Abundance is linked with nuclear stability, except for an over abundance of H from neutron emission and neutron decay near the core. The main elements in the Sun, Fe, Ni, O, Si, S, Mg, and Ca, comprise 99 percent of meteorites. Neutron emission from the SN core triggers a series of reactions that produce solar luminosity, solar neutrinos, excess H, and an annual outpouring of 2.7 E 43 Hydrogen atoms in the solar wind. 
O. Manuel, C. Bolon, M. Zhong and P. Jangam