Rogue black hole (original) (raw)

A rogue black hole (also termed a free-floating, interstellar, nomad, orphan, unbound or wandering black hole) is an interstellar object without a host galactic group. They are caused by collisions between two galaxies or when the merging of two black holes is disrupted. It has been estimated that there could be 12 rogue black holes in the Milky Way galaxy.