Question

When a red giant dies, before it becomes a WHITE DWARF (small, dim, hot star) that eventually becomes a BLACK DWARF (remnant, dark, cold matter), it explodes into what?

Answer 1

some massive black dwarfs may eventually produce supernova explosions. These will occur if pycnonuclear (density-based) fusion processes much of the star to iron, which would lower the Chandrasekhar limit for some black dwarfs below their actual mass.