NGC 7003  NGC 7003 is a spiral galaxy around 220 million light-years from Earth in the constellation Delphinus. NGC 7003 has an estimated diameter of 80,800 light-years. The galaxy was discovered by German astronomer Heinrich Louis d'Arrest on August 26, 1864. There also has been at least one supernova observed in NGC 7003. On May 12, 2011 a Type II supernova designated as SN2011dk was discovered in NGC 7003.