NGC 3978 is a large intermediate spiral galaxy with a bar[1] located in the constellation of Ursa Major.[2] It is located 460 million light-years away from the Solar System[3] and was discovered by William Herschel on March 19, 1790, but also observed by John Herschel on April 14, 1831.[4]
| NGC 3978 | |
|---|---|
 Sloan Digital Sky Survey image of spiral galaxy NGC 3978 (center) and NGC 3975 (right) | |
| Observation data | |
| Constellation | Ursa Major |
| Right ascension | 11hr 56m 10.320s |
| Declination | +60d 31m 21.11s |
| Redshift | 0.033176 |
| Heliocentric radial velocity | 9,946 km/s |
| Distance | 459 Mly (140.7 Mpc) |
| Apparent magnitude (V) | 13.4 |
| Characteristics | |
| Type | SABbc, HII, SABbc? |
| Size | 227,000 ly (approximately 69.62 kpc) |
| Apparent size (V) | 1.29 x 1.16 arcmin |
| Other designations | |
| PGC 37502, UGC 6910, CGCG 292-047, MCG +10-17-105, 2MASX J11561045+6031300, 2MASS J11561030+6031209, HOLM 306A, IRAS 11535+6047, SDSS J115610.31+603121.1, NVSS J115610+603121, 6C B115332.3+604801, [TTL2012] 088320, NFGS 100, ASK 213392.0, MaNGA 01-617857, LEDA 37502 | |
NGC 3978 has a luminosity class of II-III and it has a broad H II region which contains regions of ionized hydrogen.[3] 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
Two supernovae were discovered in NGC 3978: SN 2003cq and SN 2008l.
SN 2003cq
SN 2003cq[7] was discovered on March 30, 2003, by British astronomer Ron Arbour.[8] It was located 32".0 east and 2".3 south of the nucleus with a magnitude of 17.1.[9] This supernova was Type Ia.[7][10]
SN 2008I
SN 2008I was discovered by astronomers P. Thrasher, W. Li, and A. V. 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]