NGC 6946

NGC 6946 or Fireworks Galaxy is the name of a spiral galaxy in the constellation Cepheus on the border of the constellation Cygnus. NGC 6946 has an angular extent of 11.5 '× 9.8 ' and an apparent brightness of 9.0 mag. The galaxy is located near our galactic plane, so it is the light that comes from NGC 6946 to us, strongly darkened by gas and dust in our galaxy. This complicates the observation of this galaxy and its members and especially the determination of their distance. In particular, the removal of which is to be determined from the supernova observations, which includes not only the apparent brightness and the absolute brightness of the interstellar (in this case poorly measurable ) absorbance must be known. A study published in 1997 calculation showed a photometric distance of 6.4 megaparsecs (21 million light years ). Other measurements showed values ​​from 4.1 to 10.5 megaparsecs. NGC 6946 leads the statistics of the supernova abundances over the past 100 years with a number of nine.

NGC 6946 was discovered on September 9, 1798 by the German - British astronomer William Herschel.