View source for Sagittarius Dwarf Irregular Galaxy

{{Short description|Dwarf galaxy in the constellation of Sagittarius}}
{{Distinguish|text=[[Sagittarius Dwarf Spheroidal Galaxy]] (SagDEG), a satellite galaxy of the Milky Way}}

{{Infobox Galaxy
| name = SagDIG
| image = SagDIG.jpg
| image_size = 250px
| caption = SagDIG by [[Hubble Space Telescope]]
| credit = 
| type = IB(s)m<ref name="ned">{{cite web
  | title=NASA/IPAC Extragalactic Database
  | work=Results for Sagittarius Dwarf Irregular
  | url=http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=Sagittarius+Dwarf+Irregular#ObjNo1
  | access-date=2007-03-15 }}</ref> V ([[Dwarf irregular galaxy]])
| epoch = [[Epoch (astronomy)#Julian years and J2000|J2000]]
| ra = {{RA|19|29|59.0}}<ref name="ned" />
| dec = {{DEC|-17|40|41}}<ref name="ned" />
| dist_ly = [[1 E22 m|3.39±0.23]] [[light-year|Mly]] (1.04±0.07&nbsp;[[parsec|Mpc]])<ref name="karachentsevetal2004">{{cite journal
  | author1=Karachentsev, I.D. 
  | author2=Karachentseva, V.E. 
  | author3=Hutchmeier, W.K. 
  | author4=Makarov, D.I. 
  | title=A Catalog of Neighboring Galaxies
  | journal=Astronomical Journal
  | date=2004
  | volume=127
  | issue=4
  | pages=2031–2068
  | bibcode=2004AJ....127.2031K
  | doi=10.1086/382905| doi-access=free
  }}</ref><ref name="Karachentsevetal2006">{{cite journal
  | author1=Karachentsev, I.D.
  | author2=Kashibadze, O.G.
  | title=Masses of the local group and of the M81 group estimated from distortions in the local velocity field
  | journal=Astrophysics
  | date=2006
  | volume=49
  | issue=1
  | pages=3–18
  | bibcode=2006Ap.....49....3K
  | doi=10.1007/s10511-006-0002-6| s2cid=120973010
 }}</ref>
| appmag_v = 15.5<ref name="ned" />
| size_v = 2.9{{prime}} × 2.1{{prime}}<ref name="ned" />
| constellation name = [[Sagittarius (constellation)|Sagittarius]]
| z = &minus;79±1&nbsp;km/[[second|s]]<ref name="ned" />
| notes = 
| names = Sagittarius Dwarf Irregular,<ref name="ned" /> SGR Dwarf,<ref name="ned" /><br>ESO594-G004,<ref name="ned" /> [[Principal Galaxies Catalogue|PGC]] 63287,<ref name="ned" /> Kowal's Object<ref name="ned" />
}}
The '''Sagittarius Dwarf Irregular Galaxy''' ('''SagDIG''') is a [[dwarf galaxy]] in the [[constellation]] of [[Sagittarius (constellation)|Sagittarius]]. It lies about 3.4&nbsp;million [[light-year]]s away. It was discovered by [[Cesarsky]]{{who?|date=March 2025}} ''et&nbsp;al.'' on a [[photographic plate]] taken for the ESO&nbsp;(B) Atlas on 13&nbsp;June 1977 using the [[European Southern Observatory|ESO]] 1&nbsp;meter Schmidt telescope.

The SagDIG is thought to be the member of the [[Local Group]] most remote from the Local Group's [[Barycentric coordinates (astronomy)|barycenter]]. It is only slightly outside the [[zero-velocity surface]] of the Local Group.<ref name="Bergh2000">{{Cite journal
 | last1 = van den Bergh
 | first1 = Sidney
 | authorlink1 = Sidney van den Bergh
 | title = Updated Information on the Local Group
 | date = April 2000
 | journal = The Publications of the Astronomical Society of the Pacific
 | volume = 112
 | issue = 770
 | bibcode = 2000PASP..112..529V
 | pages = 529–536
 | doi = 10.1086/316548
|arxiv = astro-ph/0001040 | s2cid = 1805423
 }}</ref>

SagDIG is a much more luminous galaxy than the [[Aquarius Dwarf]] and it has been through a prolonged period of star formation.<ref>Momany ''et al.'' 2005.</ref> This has resulted in it containing a rich intermediate-age population of stars. Twenty-seven candidate [[Stellar classification#Class C|carbon stars]] have been identified inside SagDIG. Analysis shows that the underlying [[stellar population]] of SagDIG is [[metal-poor]] (at least [Fe/H]&nbsp;≤&nbsp;&minus;1.3). Further, the population is young, with the most likely average age between 4 and 8&nbsp;billion years for the dominant population.<ref name ="Gullieusziketal2007">{{Cite journal
 | last1 = Gullieuszik
 | first1 = M.
 | last2 = Rejkuba
 | first2 = M.
 | last3 = Cioni
 | first3 = M. R.
 | last4 = Habing
 | first4 = H. J.
 | last5 = Held
 | first5 = E. V.
 | title = Near-infrared photometry of carbon stars in the Sagittarius dwarf irregular galaxy and DDO 210
 | date = November 2007
 | journal = [[Astronomy and Astrophysics]]
 | volume = 475
 | issue = 2
 | bibcode = 2007A&A...475..467G
 | pages = 467–477
 | doi = 10.1051/0004-6361:20066848
|arxiv = 0709.0918 | s2cid = 15437439
 }}</ref>

==References==
{{reflist}}

==External links==
{{commonscat}}
* {{WikiSky|name=The Sagittarius Dwarf Irregular Galaxy}}


{{Sky|19|29|59.0|-|17|40|41|3390000}}

[[Category:Dwarf irregular galaxies]]
[[Category:Irregular galaxies]]
[[Category:Sagittarius (constellation)]]
[[Category:Local Group]]
[[Category:Principal Galaxies Catalogue objects|63287]]
[[Category:Astronomical objects discovered in 1977]]