NGC 51

NGC 51 is a lenticular galaxy in the constellation Andromeda. It has a diameter of 90,000 light-years. The galaxy was discovered on September 7, 1885, by Lewis Swift, who described it as "Pretty faint, pretty small, round, brighter middle."

One supernova, SN 2016gxp (type Ia, mag. 18.6), was discovered in NGC 51 on October 5, 2016.