NGC 2442 and NGC 2443

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.^[3] 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.^[4] Associated with this galaxy is HIPASS J0731-69, a cloud of gas devoid of any stars.^[5] It is likely that the cloud was torn loose from NGC 2442 by a companion.^[5]

NGC 2442 / 2443
NGC 2442 (upper spiral structure) and NGC 2443 (lower horizontal spiral arm)[1]
Observation data (J2000 epoch)
Constellation	Volans
Right ascension	07h 36m 23.8s[2]
Declination	−69° 31′ 51″[2]
Redshift	1466 ± 5 km/s[2]
Apparent magnitude (V)	11.2[2]
Characteristics
Type	SAB(s)bc pec[2]
Size	~160,000 ly (48.94 kpc) (estimated)[2]
Apparent size (V)	5′.5 × 4′.9[2]
Notable features	SW part is NGC 2442 while NE part is NGC 2443
Other designations
PGC 21373[2]

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.^[4][6]

Supernovae

Two, or perhaps three, supernovae have been observed in NGC 2442:

• SN 1999ga (type II, mag. 18) was discovered by the Perth Astronomical Research Group on 19 November 1999.^[7][8]
• SN 2015F (type Ia, mag. 16.8) was discovered by Libert "Berto" Monard on 9 March 2015.^[9][10] It reached magnitude 12.9, making it the brightest supernova of 2015.^[11]

• Gaia16cfr, also known as AT 2016jbu,^[12][13] 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.^[14] However, a paper published in August 2022 suggested that this was a genuine, but strange, supernova.^[15]