NGC 3746

NGC 3746 is a large barred spiral galaxy with a ring structure^[2] located in the Leo constellation.^[3] It is located 449 million light-years from the Solar System and has an approximate diameter of 45,000 light-years.^[1] NGC 3746 was discovered by Ralph Copeland on 9 February 1874 with subsequent observations made by Hermann Kobold, Lawrence Parsons and John Louis Emil Dreyer.^[4]

NGC 3746
NGC 3746 (center) with NGC 3745 (left), imaged by Kitt Peak National Observatory
Observation data (J2000 epoch)
Constellation	Leo
Right ascension	11h 37m 43.6312s[1]
Declination	+22° 00′ 35.153″[1]
Redshift	0.030072[1]
Heliocentric radial velocity	9,015 ± 2 km/s[1]
Distance	449.2 ± 31.5 Mly (137.72 ± 9.65 Mpc)[1]
Group or cluster	Copeland Septet
Apparent magnitude (V)	15.01[1]
Characteristics
Type	SB(r)b[1]
Size	~44,400 ly (13.62 kpc) (estimated)[1]
Apparent size (V)	1.1′ × 0.5′[1]
Other designations
Copeland Septet NED02, HCG 057B, 2MASS J11374363+2200353, 2MASX J11374364+2200349, UGC 6597, LEDA 35997, MCG +04-28-005, PGC 35997, CGCG 127-006, SDSS J113743.62+220035.3[1]

The luminosity class of NGC 3746 is II and it has a broad H II region with a recessed core (RET).^[1]

Copeland Septet

Copeland Septet with NGC 3746 in bottom right, imaged by Mount Lemmon Observatory

NGC 3746 is a member of the Copeland Septet which comprises 7 galaxies discovered by Copeland in 1874.^[5] The other 6 members are NGC 3745, NGC 3748, NGC 3750, NGC 3751, NGC 3753, and NGC 3754. Together, they are known as Hickson 57 and Arp 320.^[6]

Supernovae

Two supernovae have been discovered in NGC 3746:

• SN 2002ar (Type Ia, mag. 16.5)^[7] was discovered by Dr W. D. Li from the University of California, Berkeley via unfiltered CCD images which was taken by the 0.8-m Katzman Automatic Imagining Telescope on 3 and 4 February 2002.^[8] It was located 3".3 east and 0".5 south of the nucleus.^[8][9]
• SN 2005ba (Type II, mag. 17.5)^[10] was discovered on 1 April 2005 by Norwegian scientists Arne Danielsen, Mikkel Steine, and Stale Kildahl via unfiltered images taken from a 'Celestron 14' reflector at Veggli, Norway.^[11] It was located 14".6 west and 4".0 north of the nucleus.^[12][13]