| Andromeda XIX | |
|---|---|
| Observation data (J2000 epoch) | |
| Constellation | Andromeda |
| Right ascension | 00h 19m 32.10s |
| Declination | +35° 02′ 37.1″ |
| Redshift | 0.003903 |
| Distance | 2,651 kly (812.8 kpc) |
| Apparent magnitude (V) | −10.1 |
| Absolute magnitude (V) | 14.5 |
| Characteristics | |
| Type | dG |
| Half-light radius (physical) | 1700 pc |
| Notable features | Satellite of Andromeda Galaxy, extremely diffuse |
| Other designations | |
| And XIX, LEDA 5056919 | |
Andromeda XIX is a satellite galaxy of the Andromeda Galaxy (M31), a member of the Local Group, like the Milky Way Galaxy. Andromeda XIX is considered "the most extended dwarf galaxy known in the Local Group", and has been shown to have a half-light radius of 1.7 kiloparsec (kpc). It was discovered by the Canada–France–Hawaii Telescope, and is thought to be a dwarf galaxy.
As with other dwarf galaxies, Andromeda XIX is not producing new stars: 90% of its star formation occurred over 9 billion years ago. However, compared to dwarf galaxies of similar mass Andromeda XIX is extremely diffuse, like Antlia II.
Surveillance was performed during use of the MegaPrime/MegaCam 1 deg2 (camera) on the Canada-France-Hawaii Telescope (CFHT) had mapped the Andromeda Galaxy's stellar halo (one quarter) up to ~150 kpc. The survey confirmed the clumpiness of Andromeda's stellar halo. It had shown the existence of multiple other dwarf galaxies. They include: Andromeda XI, XII, XIII, XV, XVI, XVIII, XIX, and XX.