Discovered by Caroline Herschel in 1783
NGC 891 is a spiral galaxy located approximately 30 million light years from Earth in the constellation Andromeda. The orientation of the galaxy is almost edge on. This view emphasizes just how thin and flat a spiral galaxy is. This orientation also displays the very prominent dust band along the plane of its disk. NGC 891 is thought to be much like our Milky Way. Studies show many similarities in size, shape, and luminosity. Measurements of the dynamics of NGC 891ís molecular hydrogen component indicate the likely presence of a central bar much like the one in the Milky Way.