Fireworks Galaxy (NGC 6946) in Cepheus
NGC 6946, (also known as the Fireworks Galaxy, Arp 29, and Caldwell 12), is an mixed spiral galaxy about 18 million light-years away, in the constellation of Cepheus. Its estimated linear diameter is 58’000 light-years, shining at magnitude 8.8.
It was discovered by William Herschel on September 9, 1798. NGC 6946 is highly obscured by interstellar matter of the Milky Way galaxy, as it is quite close to the galactic plane. Nine supernovae since 1917 have been observed in NGC 6946.
[description from wikipedia and O’Meara]