Sagittarius Dwarf Irregular Galaxy
- Not to be confused with the Sagittarius Dwarf Elliptical Galaxy.
| SagDIG | |
|---|---|
SagDIG by Hubble Space Telescope
|
|
| Observation data (J2000 epoch) | |
| Constellation | Sagittarius |
| Right ascension | 19h 29m 59.0s[1] |
| Declination | −17° 40′ 41″[1] |
| Redshift | -79 ± 1 km/s[1] |
| Distance | 3.39 ± 0.23 Mly (1.04 ± 0.07 Mpc)[2][3] |
| Type | IB(s)m[1] V (Dwarf irregular galaxy) |
| Apparent dimensions (V) | 2′.9 × 2′.1[1] |
| Apparent magnitude (V) | 15.5[1] |
| Other designations | |
| Sagittarius Dwarf Irregular,[1] SGR Dwarf,[1] ESO594-G004,[1] PGC 63287,[1] Kowal's Object[1] |
|
The Sagittarius Dwarf Irregular Galaxy or SagDIG is a dwarf galaxy in the constellation of Sagittarius. It lies about 3.4 million light-years away. SagDIG should not be confused with the Sagittarius Dwarf Elliptical Galaxy or SagDEG, a satellite galaxy of the Milky Way. It was discovered by Cesarsky et al. on a photographic plate taken for the ESO (B) Atlas on June 13, 1977 using the ESO 1 meter Schmidt telescope.
The SagDIG is the most remote object from the barycenter thought to be a member of the Local Group. It is only slightly outside the zero-velocity surface of the Local Group.[4]
SagDIG is a much more luminous galaxy than Aquarius Dwarf and it has been through a prolonged star formation (Momany et al. 2005). This has resulted in it containing a rich intermediate-age population of stars. Twenty-seven candidate carbon stars have been identified inside SagDIG. Analysis shows that the underlying stellar population of SagDIG is metal-poor (at least [Fe/H] ≤ −1.3). Further, the population is young, with the most likely average age between 4 and 8 billion years for the dominant population.[5]
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
External links
- The Sagittarius Dwarf Irregular Galaxy on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
