Two supernovae have been identified in M74:[2] SN 2002ap[7] and SN 2003gd.[8]
SN 2002ap has attracted considerable attention because it is one of the few Type Ic supernovae (or hypernovae) observed within 10 Mpc in recent years.[9][10][11] This supernovae has been used to test theories on the origins of similar Type Ic supernovae at higher distances[10] and theories on the connection between supernovae and gamma ray bursts.[11]
SN 2003gd is a Type II-P supernova.[12] Type II supernovae have known luminosities, so they can be used to accurately measure distances. The distance measured to M74 using SN 2003gd is 9.6 ± 2.8 Mpc, or 31 ± 9 million ly.[3] For comparison, distances measured using the brightest supergiants are 7.7 ± 1.7 Mpc and 9.6 ± 2.2 Mpc.[3] Ben E. K. Sugerman found a "light echo" - a reflection of supernova explosion that appeared after the explosion itself - associated with SN 2003gd.[13] This is one of the few supernovae in which such a reflection has been found. This reflection appears to be from dust in a sheet-like cloud that lies in front of the supernova, and it can be used to determine the composition of the interstellar dust.[13][14]
-Wikipedia
http://en.wikipedia.org/wiki/Messier_74
Topic: NGC 2535/2536, M66, and M74 (Read 7655 times)
