The story begins when 1) an aging star swells to a red giant, and 2) it explodes in a Type II, Type Ib, or Type Ic supernova, then 3) it leaves behind a cooling core that forms the ultradense neutron...
A neutron star is a type of stellar remnant that results from the gravitational collapse of a massive star during a supernova. Such stars are composed almost entirely of neutrons, which are subatomic...