Changes

: When a [[massive]] [[star]] runs out of [[Helium]] to [[Nuclear Fusion|fuse]] the core collapses rapidly. Eventually the [[element]]s collide with one another and rebound outwards into an explosion known as a [[supernova]] which can be brighter than all the other [[star]]s in a [[galaxy]] put together.

: The [[supernova]] will leave behind a core which is either a [[Neutron Star|neutron star]] or a [[Black Hole|black hole]] depending on its [[mass]]. The greater [[mass]] becomes a [[Black Hole|black hole]].