NGC 2442 and NGC 2443 explained

NGC 2442 / 2443
Type:	SAB(s)bc pec^[1]
Z:	1466 ± 5 km/s
Appmag V:	11.2
Size V:	5′.5 × 4′.9
Constellation Name:	Volans
Notes:	SW part is NGC 2442 while NE part is NGC 2443
Names:	PGC 21373

NGC 2442 and NGC 2443 are two parts of a single intermediate spiral galaxy, commonly known as the Meathook Galaxy or the Cobra and Mouse.^[2] It is about 50 million light-years away in the constellation Volans. It was discovered by Sir John Herschel on December 23, 1834 during his survey of southern skies with a 18.25 inch diameter reflecting telescope (his "20-foot telescope") from an observatory he set up in Cape Town, South Africa.^[3] Associated with this galaxy is HIPASS J0731-69, a cloud of gas devoid of any stars.^[4] It is likely that the cloud was torn loose from NGC 2442 by a companion.^[4]

When John Louis Emil Dreyer compiled the New General Catalogue of Nebulae and Clusters of Stars he used William Herschel's earlier observations that described two objects in a "double nebula", giving the northern most the designation NGC 2443 and the southernmost most the designation NGC 2442. Herschel's later observations noted that the two objects were actually a single large nebula.^{[5] [6]}

Supernovae

Two supernovae have been observed in NGC 2442: SN 1999ga (type II, mag. 18),^[7] and SN 2015F (type Ia, mag. 16.8).^[8]

Gaia16cfr was a supernova imposter that occurred in NGC 2442 on 1 December 2016. It reached a Gaia apparent magnitude of 19.3 and absolute magnitude of about -12.^[9]

External links

• NGC 2442 in Volans
• Astronomy Picture of the Day
  • NGC 2442: Galaxy in Volans 2007 March 15
  • NGC 2442: Galaxy in Volans 2010 March 25 - from Hubble Space Telescope data
  • NGC 2442: Galaxy in Volans 2017 August 17- from Hubble Space Telescope and European Southern Observatory data

Notes and References

1. Web site: NASA/IPAC Extragalactic Database . Results for NGC 2442 / 2443 . 2023-02-08 .
2. Book: Chadwick . S . Cooper . I . Imaging the Southern Sky . 11 December 2012 . Springer . New York . 978-1461447498 . 263.
3. Web site: Seligman. Courtney. Celestial Atlas: NGC Objects: NGC 2400 - 2449. cseligman.com. 10 July 2015. https://web.archive.org/web/20150909235357/http://cseligman.com/text/atlas/ngc24.htm#2443. 9 September 2015. dead.
4. Ryder, S.D.. HIPASS Detection of an Intergalactic Gas Cloud in the NGC 2442 Group . The Astrophysical Journal . 555 . 1 . 232–239 . July 2001 . 2001ApJ...555..232R . etal. astro-ph/0103099. 10.1086/321453. 14455875 .
5. Web site: Seligman. Courtney. Celestial Atlas: NGC Objects: NGC 2400 - 2449. cseligman.com. 10 July 2015. https://web.archive.org/web/20150909235357/http://cseligman.com/text/atlas/ngc24.htm#2443. 9 September 2015. dead.
6. https://ngcicproject.observers.org/NGC/NGC_24xx/NGC_2443.htm NGC/IC Project Restoration Effortngcicproject.observers.org
7. https://www.wis-tns.org/object/1999ga Transient Name Server entry for SN 1999ga.
8. https://www.wis-tns.org/object/2015F Transient Name Server entry for SN 2015F.
9. 2018MNRAS.473.4805K. Connecting the progenitors, pre-explosion variability and giant outbursts of luminous blue variables with Gaia16cfr. Monthly Notices of the Royal Astronomical Society. 473. 4. 4805. Kilpatrick. Charles D.. Foley. Ryan J.. Drout. Maria R.. Pan. Yen-Chen. Panther. Fiona H.. Coulter. David A.. Filippenko. Alexei V.. Marion. G. Howard. Piro. Anthony L.. Rest. Armin. Seitenzahl. Ivo R.. Strampelli. Giovanni. Wang. Xi E.. 2018. 10.1093/mnras/stx2675. 1706.09962.