IC 1613
| IC 1613 | |
|---|---|
IC 1613 captured with the VLT's OmegaCAM. | |
| Observation data (J2000 epoch) | |
| Constellation | Cetus |
| Right ascension | 01h 04m 47.8s |
| Declination | +02° 07′ 04″ |
| Redshift | −234±1 km/s |
| Distance | 2.38±0.07 Mly (730±20 kpc) |
| Group or cluster | Local Group |
| Apparent magnitude (V) | 9.9 |
| Absolute magnitude (V) | −15.2 |
| Characteristics | |
| Type | IB(s)m |
| Mass | (1.1±0.2)×108 M☉ |
| Apparent size (V) | 16.2′ × 14.5′ |
| Other designations | |
| UGC 668, DDO 8, PGC 3844, Caldwell 51 | |
IC 1613 (also known as Caldwell 51) is an irregular dwarf galaxy located on the outskirts of the Local group around 730 kiloparsecs from Earth in the constellation of Cetus near the star 26 Ceti. It has a low mass with its mass only being around 10^8 solar masses. It has played an important role in the calibration of the Cepheid variable period-luminosity relation for estimating distances. Other than the Magellanic Clouds, it is one of the few Local Group dwarf irregular galaxy where RR Lyrae-type variables have been observed; this factor, along with an unusually low abundance of interstellar dust both within IC 1613 and along the line of sight enable especially accurate distance estimates. IC 1613 was discovered in 1906 by Max Wolf, and is approaching Earth at 234 km/s.
There are many faint galaxies close to IC 1613, 14 of which are catalogued as members of a yet-unnamed galaxy cluster located at z≈0.20.