| UGC 1840 | |
|---|---|
 UGC 1840 imaged by the Hubble Space Telescope | |
| Observation data (J2000 epoch) | |
| Constellation | Andromeda |
| Right ascension | 02h 23m 08.4268s [1] |
| Declination | +41° 22′ 20.031″ [1] |
| Redshift | 0.018096 |
| Heliocentric radial velocity | 5,420 km/s |
| Distance | 258.5 Mly (79.1 Mpc) |
| Characteristics | |
| Type | Peculiar |
| Size | ~131,100 ly (40.20 kpc) (estimated) |
| Notable features | Collisional ring galaxy |
| Other designations | |
| IRAS 02200+4108, 2MASX J02231142+4122047, Arp 145, MCG +07-06-002, PGC 9060 & 9062, CGCG 538-056, HFLLZOA F264, V Zw 229 | |
UGC 1840, also known as Arp 145, are a pair of interacting galaxies located 250 million light-years away from the Solar System in the Andromeda constellation. [2] The earliest known reference to the pair of galaxies is in part 2 of the Morphological Catalogue of Galaxies, published in 1964, where it is listed as MCG +07-06-002. [3]
Made up of two galaxies, UGC 1840 NED01 (PGC 9060) [4] and UGC 1840 NED02 (PGC 9062), [5] the two galaxies had recently collided with each other [6] in which the elliptical galaxy has penetrated through the spiral galaxy's nucleus leaving a hole in its middle, thus forming a ring galaxy. [7] [8] With a diameter of 1.3 arc minutes, close to 100,000 thousand light-years, they are roughly the same size as the Milky Way. [9] [ unreliable source? ]
Both galaxies are listed as Arp 145 in the Atlas of Peculiar Galaxies which was created by Halton Arp. [10] [11] They fall under the category of objects that have emanating material and both classified as galaxies that have ring systems.
