| NGC 1421 | |
|---|---|
 NGC 1421 by Legacy Surveys DR10 | |
| Observation data (J2000epoch) | |
| Constellation | Eridanus |
| Right ascension | 03h 42m 29.3s[1] |
| Declination | −13° 29′ 17″[1] |
| Redshift | 0.006971 ± 0.000017[1] |
| Heliocentric radial velocity | 2,090 ± 5 km/s[1] |
| Distance | 69.1 ± 17Mly (21.2 ± 5.2Mpc)[1] |
| Group orcluster | Eridanus Group |
| Apparent magnitude (V) | 11.4[2] |
| Characteristics | |
| Type | SAB(rs)bc[1] |
| Apparent size (V) | 3.5′ × 0.9′[1] |
| Other designations | |
| MCG -02-10-008, IRAS 03401-1338,PGC 13620 | |
NGC 1421 is aspiral galaxy in the constellationEridanus. The galaxy lies about 70 millionlight years away from Earth, which means, given its apparent dimensions, that NGC 1421 is approximately 70,000 light years across.[1] It was discovered byWilliam Herschel on February 1, 1785.[3] It is a member of theEridanus Group.
The galaxy is seen nearly edge-on. It has a bright nucleus with a diffuse bar and two asymmetric high surface brightness spiral arms. The southern arm emerges from the bar, bends slightly to the south and after that it appears straight up to the edge of the galaxy. After that it bends eastwards and fades. The southern arms have several star forming regions. One or two armlets are visible east of the southern arm. The northern arm emerges east of the bar, bends westwards and breaks in two branches. The western branch has higher surface brightness, bright knots, and ends at an elongated bright knot. The eastern branch is smooth.[4]
The observed asymmetry appears to be the result of aninteraction or a merger. Radio imaging of the CO line shows an additional kinetic component, which has a relative speed of 300 km/s with respect to the rest of the galaxy. This feature corresponds to a disturbance in the central and north part of the galaxy inH-alpha imaging. The multiple star forming regions in the arms of the galaxy are also indicative of an interaction.[5]
The nucleus appears to beactive, categorised as an HII region based on its opticalspectrum,[6] and has radio emission which spans for several hundred parsecs. The galaxy has X-ray emission which extends beyond the visual disk of the galaxy, mostly towards the south.[7]
NGC 1421 is the foremost galaxy of the NGC 1421 group, which also includes MCG -02-10-009. The group belong to theEridanus Group, which also includes theFornax Cluster and theEridanus Cluster.[8] The galaxy has a dwarf companion galaxy which has two bright nuclearHII regions.[9]
