Stars in Intergalactic Space

Stars reside in galaxies, right? Well, apparently not always. Careful study of some clusters of galaxies reveals a substantial number, perhaps as high as 10%, of stars are found in the voids between galaxies, not bound to any single galaxy. These stars are believed to have been stripped from galaxies in the cluster when they collided, ending up unbound to either colliding galaxy. There is even evidence that stars may form in regions between galaxies when gas clouds collide.