Cause Supernova nucleosynthesis

a supernova massive explosion of star occurs under 2 principal scenarios. first white dwarf star undergoes nuclear-based explosion after reaches chandrasekhar limit after absorbing mass neighboring star (usually red giant). second, , more common, cause when massive star, supergiant, reaches nickel-56 in nuclear fusion (or burning) processes. isotope undergoes radioactive decay iron-56, has 1 of highest binding energies of of isotopes, , last element produces net release of energy nuclear fusion, exothermically.

all nuclear fusion reactions produce heavier elements cause star lose energy , said endothermic reactions. pressure supports star s outer layers drops sharply. outer envelope no longer sufficiently supported radiation pressure, star s gravity pulls outer layers rapidly inward. star collapses, these outer layers collide incompressible stellar core, producing shockwave expands outward through unfused material of outer shell. pressures , densities in shockwave sufficient induce fusion in material, , energy released leads star s explosion, dispersing material star interstellar space.