Arp 220 is an ultraluminous starburst galaxy located 250 million light years away in the constellation Serpens. The galaxy is the product of a collision of two smaller galaxies. The merger remnant has an apparent magnitude of 13.9 and an apparent size of 1.5 by 1.2 arcminutes, corresponding to a diameter of 110,000 light-years. The… Read More »Arp 220
