This particular event is a type-2 supernova. Type-2 means that hydrogen is fully present in the emission spectra, which implies that this is not a type-1 deton

This particular event is a type-2 supernova. Type-2 means that hydrogen is fully present in the emission spectra, which implies that this is not a type-1 detonation of a white dwarf. Type-2 means the end of "silicon burning" and the collapse of an iron core. Iron is the ultimate "ash" of a stellar core. This explains the final stage of silicon burning, which lasts hours. https://en.m.wikipedia.org/wiki/Silicon-burning_process https://en.m.wikipedia.org/wiki/Silicon-burning_process