After a supernova explosion, the dead star either turns into a black hole or a
neutron star. As you might have seen in the Supernova
section, no one has found any black holes yet, but many neutron stars have been found. In
a regular atom, neutrons, protons, and electrons are inside. In a neutron stars
atom, only neutrons are in the atoms. Just a spoonful of neutron star material would weigh
an AMAZING BILLION TONS. Neutron stars spin very rapidly, making lots of energy as they
rotate. Astronomers use this energy to detect the stars.