SagDIG | |
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![]() 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] |
Apparent magnitude (V) | 15.5 [1] |
Characteristics | |
Type | IB(s)m [1] V ( Dwarf irregular galaxy) |
Apparent size (V) | 2.9′ × 2.1′ [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 (SagDIG) is a dwarf galaxy in the constellation of Sagittarius. (SagDIG should not be confused with the Sagittarius Dwarf Spheroidal Galaxy, SagDEG, a satellite galaxy of the Milky Way discovered decades later in the same constellation.) It lies about 3.4 million light-years away. It was discovered by Cesarsky et al. on a photographic plate taken for the ESO (B) Atlas on 13 June 1977 using the ESO 1 meter Schmidt telescope.
The SagDIG is thought to be the member of the Local Group most remote from the Local Group's barycenter. It is only slightly outside the zero-velocity surface of the Local Group. [4]
SagDIG is a much more luminous galaxy than the Aquarius Dwarf and it has been through a prolonged period of star formation. [5] 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. [6]
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] |
Apparent magnitude (V) | 15.5 [1] |
Characteristics | |
Type | IB(s)m [1] V ( Dwarf irregular galaxy) |
Apparent size (V) | 2.9′ × 2.1′ [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 (SagDIG) is a dwarf galaxy in the constellation of Sagittarius. (SagDIG should not be confused with the Sagittarius Dwarf Spheroidal Galaxy, SagDEG, a satellite galaxy of the Milky Way discovered decades later in the same constellation.) It lies about 3.4 million light-years away. It was discovered by Cesarsky et al. on a photographic plate taken for the ESO (B) Atlas on 13 June 1977 using the ESO 1 meter Schmidt telescope.
The SagDIG is thought to be the member of the Local Group most remote from the Local Group's barycenter. It is only slightly outside the zero-velocity surface of the Local Group. [4]
SagDIG is a much more luminous galaxy than the Aquarius Dwarf and it has been through a prolonged period of star formation. [5] 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. [6]