UGC 9128 is a dwarf irregular galaxy around 6.8–7.8 Mly (2.1–2.4 Mpc) away; it is thought to be in the Local Group, although its membership is not certain.[2][3] The galaxy has a mass of about (1.3±0.2)×107 M☉, around 100 million stars, and a diameter of around 3300 ly.[3][5] It is therefore quite faint, and so was only discovered in the 20th century.[2]
| UGC 9128 | |
|---|---|
 UGC 9128 | |
| Observation data (J2000 epoch) | |
| Constellation | Boötes |
| Right ascension | 14h 15m 56.70s[1] |
| Declination | 23° 03′ 16.2″[1] |
| Distance | 6.8–7.8 Mly (2.1–2.4 Mpc)[2][3] |
| Characteristics | |
| Type | dIrr[4] |
| Mass | (1.3±0.2)×107 [3] M☉ |
| Size | 3300 ly[5] |
| Other designations | |
| UGC 9128, DDO 187[6],PGC 50961 | |
UGC 9128 is around 2.7 Mly from GR 8, which is its nearest neighbour.[6]
UGC 9128 is a starburst galaxy, with the peak of star formation being 20–100 million years ago.[3][6] It is thought to have both a halo and disc.[6]