NGC 3938 is anunbarred spiral galaxy in theUrsa Major constellation. It was discovered by German-British astronomerWilliam Herschel on 6 February 1788.[3] It is one of the brightest spiral galaxies in the Ursa Major South galaxy group and is roughly 76,000light years in diameter.[2][4] It is approximately 41.4 million light years away fromEarth.[1] NGC 3938 is classified as type Sc under theHubble sequence, a loosely wound spiral galaxy with a smaller and dimmer bulge.[5] The spiral arms of the galaxy contain many areas ofionized atomic hydrogen gas, more so towards the center.[6]
Fivesupernovae have been identified within NGC 3938:
SN 1961U (TypeII, mag. 13.7) was discovered byPaul Wild on 28 December 1961.[11][12] [Note: some sources incorrectly list the discovery date as 2 January 1962.]
SN 1964L (TypeIc, mag. 13.3) was discovered by Paul Wild on 11 December 1964.[13][14]
SN 2005ay (Type II, mag. 15.6) was discovered byDoug Rich on 27 March 2005.[15][16][17]
SN 2017ein (Type Ic, mag. 17.6) was discovered by Ron Arbour on 25 May 2017 and peaked at magnitude 14.9.[18][19] Images taken before the explosion point to a progenitor mass between ~47-48M☉, if it was in a single star system, and ~60-80M☉, if it was in abinary star system.[20]
^"SN1961U".Transient Name Server.IAU. Retrieved27 November 2024.
^Thernoe, K. A. (4 January 1962)."Circular No. 1787 (sides 2 and 3)".Central Bureau for Astronomical Telegrams. Observatory Copenhagen. Retrieved27 November 2024.
^"SN1964L".Transient Name Server.IAU. Retrieved27 November 2024.
^Thernoe, K. A. (29 December 1964)."Circular No. 1882 (side 1)".Central Bureau for Astronomical Telegrams. Observatory Copenhagen. Retrieved27 November 2024.
![Artist's impression of progenitor star to a type Ic supernova in NGC 3938.[23]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aArtist%2527s_impression_of_progenitor_star_to_a_type_Ic_supernova.jpg)
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Media related toNGC 3938 at Wikimedia Commons
