NGC 6946

NGC 6946 is a nearby, face-on spiral galaxy on the border of Cepheus and Cygnus. Its high rate of observed supernovae earned it the nickname Fireworks Galaxy.

SN 2017eaw: A Type II supernova discovered in NGC 6946 in 2017. One of the galaxy’s most recent well-studied supernovae.
Core-collapse supernova: An explosion caused when a massive star’s core collapses at the end of its life. Most of NGC 6946’s observed supernovae belong to this broad class.
Spiral galaxy: A galaxy with a flattened disk and spiral patterns of stars, gas, and dust. NGC 6946’s prominent arms place it in this galaxy class.
Milky Way: The barred spiral galaxy containing the Sun and Solar System. It is another nearby spiral galaxy, but its dust obscures many regions from our viewpoint.
SN 2004et: A Type II supernova discovered in NGC 6946 in 2004. Its progenitor was identified in archival images, helping establish the star’s nature before explosion.
Star formation: The process by which dense regions of gas collapse to form stars. Its active star formation produces massive stars that later explode as supernovae.
Cepheus: A northern constellation bordered by Cygnus, Cassiopeia, and Draco. NGC 6946 lies in the direction of Cepheus, near the Cygnus boundary.
Messier 101: A large, face-on spiral galaxy in the constellation Ursa Major. Its open spiral arms offer a comparison with NGC 6946’s more tightly structured disk.
SN 2002hh: A Type II supernova discovered in NGC 6946 in 2002. Its heavy interstellar extinction made it a notable case for studying dust along the line of sight.
Massive star: A star substantially more massive than the Sun, with a short lifetime and energetic evolution. Massive stars are the progenitors of the galaxy’s core-collapse supernovae.

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Flocculent spiral galaxyRelated: Its many bright, irregularly distributed regions reveal how local star formation shapes spiral appearance.