NGC 550
NGC 550 is a spiral galaxy in the constellation Cetus. It is estimated to be about 300 million light-years from the Milky Way and has a diameter of approximately 110,000 light years. The German-British astronomer William Herschel discovered it on 8 October 1785.
One supernova has been observed in NGC 550: SN 1961Q was discovered by Milton Humason on 30 November 1961.