NGC 3938 explained

NGC 3938
Epoch:J2000
Type:SA(s)c[1]
Ra:[2]
Dist Ly:43 Mly
Appmag V:10.9
Size V:5.4 × 4.9
Constellation Name:Ursa Major

NGC 3938 is an unbarred spiral galaxy in the Ursa Major constellation. It was discovered on 6 February 1788 by William Herschel. It is one of the brightest spiral galaxies in the Ursa Major South galaxy group and is roughly 67,000 light years in diameter.[3] It is approximately 43 million light years away from Earth.[2] NGC 3938 is classified as type Sc under the Hubble sequence, a loosely wound spiral galaxy with a smaller and dimmer bulge.[4] The spiral arms of the galaxy contain many areas of ionized atomic hydrogen gas, more so towards the center.[5]

Supernovae

Five supernovae have been identified within NGC 3938. SN 1961U (mag. 13.7) was discovered on 2 January 1962.[6] SN 1964L (mag. 13.3) was discovered on 11 December 1964.[7] SN 2005ay is a type II supernova that was discovered on 27 March 2005 and had a magnitude of 15.6.[8] SN 2017ein is a type Ic supernova that was discovered on 25 May 2017 and peaked at magnitude 14.9.[9] Images taken before the explosion point to a progenitor mass between ~47-48, if it was in a single star system, and ~60-80, if it was in a binary star system. SN 2022xlp is a type Ia supernova that was discovered on 13 October 2022 by Kōichi Itagaki.

Notes and References

  1. Web site: Results for object NGC 3938 (NGC 3938). NASA/IPAC Extragalactic Database. California Institute of Technology. 2021-02-28.
  2. Web site: Spiral Galaxy NGC 3839 . George Normandin . 5 May 2005 . kopernik.org . 30 December 2011.
  3. Web site: The Ursa Major Groups . Atlas of the Universe . 30 December 2011.
  4. van der Kruit . P.C. . Shostak . G.S. . Studies of Nearly Face-on Spiral Galaxies. Astronomy and Astrophysics. 105. 351–358. 1982. 1982A&A...105..351V . 25 June 2014 .
  5. Jiménez-Vicente. J.. 4 . E. Battaner . M. Rozas . H. Castañeda . C. Porcel . Fabry-Perot observations of the ionized gas in NGC 3938. Astronomy and Astrophysics. 342. 417–425. 1999. 1999A&A...342..417J. astro-ph/9811391 .
  6. https://www.wis-tns.org/object/1961U Transient Name Server entry for SN 1961U.
  7. https://www.wis-tns.org/object/1964L Transient Name Server entry for SN 1964L.
  8. Web site: Supernova 2005ay in NGC 3938. Rochester Astronomy. 29 January 2013.
  9. Web site: Supernovae 2017ein in NGC 3938. www.rochesterastronomy.org. 29 June 2017. en.