Arp 148, nicknamed Mayall's object, is the aftermath of an encounter between two galaxies, resulting in a ring-shaped galaxy and a long-tailed companion. The collision between the two parent galaxies produced a shockwave effect that first drew matter into the center and then caused it to propagate outwards in a ring. Arp 148 is located in the constellation of Ursa Major, the Great Bear, approximately 500 million light-years away.
