| NGC 3445 | |
|---|---|
 NGC 3445 byHubble Space Telescope | |
| Observation data (J2000epoch) | |
| Constellation | Ursa Major |
| Right ascension | 10h 54m 35.5s[1] |
| Declination | +56° 59′ 26″[1] |
| Redshift | 0.006831 ± 0.000003[1] |
| Heliocentric radial velocity | 2,048 ± 1km/s[1] |
| Distance | 73.8 ± 20.1Mly (22.6 ± 6.2Mpc)[1] |
| Apparent magnitude (V) | 12.3[2] |
| Characteristics | |
| Type | SAB(s)m[1] |
| Apparent size (V) | 1.6′ × 1.5′[1] |
| Notable features | Interacting galaxy |
| Other designations | |
| UGC 6021,Arp 24, VV 14a,MCG +10-16-023, IRAS 10515+5715,PGC 32772, 7C 1051+5715 | |
NGC 3445 is aMagellanic spiral galaxy in the constellationUrsa Major. The galaxy lies about 75 millionlight years away from Earth, which means, given its apparent dimensions, that NGC 3445 is approximately 35,000 light years across.[1] It was discovered byWilliam Herschel on April 8, 1793.[3]
The galaxy is included inHalton Arp'sAtlas of Peculiar Galaxies in the one-armed spiral galaxies category. The galaxy has a thick arm pattern with manyHII regions.[4] A large spiral arm is visible at the south part of the galaxy while a weaker one is visible in infrared at the north. Radio emission is observed along the arms.[5] At the end of the main spiral arm there is a smaller galaxy, lying 1.2 arcminutes from the nucleus of NGC 3445,[4] connected with a weak bridge.[6]
In theinfrared are visible four bright locations of active star formation. The brightest of these infrared knots hosts five youngmassive star clusters, all being formed by a single giantmolecular cloud. The age of the clusters was determined to be 3 to 5 million years and their mass to be around105 M☉.[7] Another large star cluster lies at the nucleus of the galaxy and could be in the process of forming abulge.[5] The total star formation rate of the galaxy is estimated to be around 1M☉ per year.[5] The star formation as well as the shape of the galaxy could be the result of interaction with other galaxies.[7]
NGC 3445 forms a triplet withNGC 3440, which lies 9.9 arcminutes away, andNGC 3458, which lies 14 arcminutes away.[4] These galaxies comprise the LGG 226 group.[8] It belongs to the same galaxy cloud asNGC 3610.[9]
