Sagittarius Dwarf Irregular Galaxy

Short description: Dwarf galaxy in the constellation of Sagittarius

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]

## References

1. ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 "NASA/IPAC Extragalactic Database". Results for Sagittarius Dwarf Irregular. http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=Sagittarius+Dwarf+Irregular#ObjNo1.
2. ↑ Karachentsev, I.D.; Karachentseva, V.E.; Hutchmeier, W.K.; Makarov, D.I. (2004). "A Catalog of Neighboring Galaxies". Astronomical Journal 127 (4): 2031–2068. doi:10.1086/382905. Bibcode: 2004AJ....127.2031K.
3. ↑ Karachentsev, I.D.; Kashibadze, O.G. (2006). "Masses of the local group and of the M81 group estimated from distortions in the local velocity field". Astrophysics 49 (1): 3–18. doi:10.1007/s10511-006-0002-6. Bibcode: 2006Ap.....49....3K.
4. ↑ van den Bergh, Sidney (April 2000). "Updated Information on the Local Group". The Publications of the Astronomical Society of the Pacific 112 (770): 529–536. doi:10.1086/316548. Bibcode: 2000PASP..112..529V.
5. ↑ Momany et al. 2005.
6. ↑ Gullieuszik, M.; Rejkuba, M.; Cioni, M. R.; Habing, H. J.; Held, E. V. (November 2007). "Near-infrared photometry of carbon stars in the Sagittarius dwarf irregular galaxy and DDO 210". Astronomy and Astrophysics 475 (2): 467–477. doi:10.1051/0004-6361:20066848. Bibcode: 2007A&A...475..467G.

## External links

*   * The Sagittarius Dwarf Irregular Galaxy on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images

Coordinates:  19h 29m 59.0s, −17° 40′ 41″

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Sagittarius Dwarf Irregular Galaxy. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:Sagittarius_Dwarf_Irregular_Galaxy&oldid=3355947"