What happened to the giant star that exploded creating our sun, solar system and metal?
Is that too a White Dwarf floating somewhere?
A type II supernova (it sez here) results from the precipitous collapse of the iron accumulated at the stellar core, when the mass of it reaches about 1.4 times the mass of our Sun. There's an enormous release of energy, which produces heavier elements through fission, and along with the lighter elements from the originating red giant, this material gets blown off by the shock wave and the energy (lasting weeks or months) generated by the iron core collapse. The wave of material goes off in all directions in a more or less spherical manner, with the lighter stuff accelerated to higher velocities. Supernova debris waves can have serious consequences to the innocent bystanders, such as the people of Earth, and given the distances involved, they arrive without warning. The remaining core material from the supernova either turns into a neutron star, or a black hole, depending on the mass.