NGC 3978 is a large intermediate spiral galaxy with a bar[2] located in the constellation of Ursa Major.[3] It is located 460 million light-years away from the Solar System[1] and was discovered by William Herschel on March 19, 1790, but also observed by John Herschel on April 14, 1831.[4]

NGC 3978 has a luminosity class of II-III and it has a broad H II region which contains regions of ionized hydrogen.[1] In addition, it is categorized as a LINER galaxy by SIMBAD,[5] meaning its nucleus presents an emission spectrum which is characterized by broad lines of weakly ionized atoms.[5]

According to Vaucouleurs and Corwin, NGC 3978 and NGC 3975 form a galaxy pair with each other.[6]

Supernovae

Four supernovae have been observed NGC 3978:

  • SN 2003cq[7] was discovered on March 30, 2003, by British astronomer Ron Arbour.[8] It was located 32" east and 2.3" south of the nucleus with a magnitude of 17.1.[9] This supernova was Type Ia.[7][10]
  • SN 2008I was discovered by astronomers P. Thrasher, W. Li, and Alex Filippenko as part of Lick Observatory Supernova Search (LOSS) on January 2, 2008.[11] It was located 3.7" west and 10.4" north of the nucleus with magnitude of 19.1.[12] The supernova was Type II[13] which possibly resulted from a collapse of a massive star.[14]
  • SN 2020kay (type II, mag. 18.5) was discovered by ATLAS on 15 May 2020.[15]
  • SN 2025ddb (type II, mag. 18.566) was discovered by ATLAS on 2 March 2025.[16]

References

  1. ^ a b c d e f "Results for object NGC 3978". NASA/IPAC Extragalactic Database. NASA and Caltech. Retrieved 2024-05-06.
  2. ^ "HyperLeda -object description". atlas.obs-hp.fr. Retrieved 2024-05-06.
  3. ^ "NGC 3978". spider.seds.org. Retrieved 2024-05-10.
  4. ^ "New General Catalog Objects: NGC 3950 - 3999". cseligman.com. Retrieved 2024-05-06.
  5. ^ a b "NGC 3978 - LINER-type Active Galaxy Nucleus". simbad.u-strasbg.fr. Retrieved 2024-05-06.
  6. ^ de Vaucouleurs, G.; de Vaucouleurs, A.; Corwin, H. G., Jr. (1976-01-01). Second reference catalogue of bright galaxies. Containing information on 4,364 galaxies with references to papers published between 1964 and 1975. Bibcode:1976srcb.book.....D.{{cite book}}: CS1 maint: multiple names: authors list (link)
  7. ^ a b "SN 2003cq | Transient Name Server". www.wis-tns.org. Retrieved 2024-05-06.
  8. ^ "Ron Arbour - Supernova hunter and astrophotographer". mstecker.com. Retrieved 2024-05-06.
  9. ^ "Bright Supernovae - 2003". www.rochesterastronomy.org. Retrieved 2024-05-06.
  10. ^ Pan, Yen-Chen (2020). "High-velocity Type Ia Supernova Has a Unique Host Environment". The Astrophysical Journal Letters. 895 (1): L5. arXiv:2004.14544. Bibcode:2020ApJ...895L...5P. doi:10.3847/2041-8213/ab8e47.
  11. ^ "SN 2008I". w.astro.berkeley.edu. Retrieved 2024-05-06.
  12. ^ "Bright Supernovae - 2008". www.rochesterastronomy.org. Retrieved 2024-05-06.
  13. ^ "SN 2008I | Transient Name Server". www.wis-tns.org. Retrieved 2024-05-06.
  14. ^ "Type II Supernovae - an overview | ScienceDirect Topics". www.sciencedirect.com. Retrieved 2024-05-06.
  15. ^ "SN 2020kay". Transient Name Server. IAU. Retrieved 2 March 2025.
  16. ^ "SN 2025ddb". Transient Name Server. IAU. Retrieved 12 March 2025.
Allikas: https://en.wikipedia.org/wiki/NGC_3978
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