Sagittarius Dwarf Irregular Galaxy

Infobox Galaxy
name = SagDIG


caption = SagDIG by Hubble Space Telescope
credit = NASA/ESA/STScI/AURA
type = IB(s)mcite 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
accessdate=2007-03-15 ] V (Dwarf irregular galaxy)
epoch = J2000
ra = RA|19|29|59.0
dec = DEC|-17|40|41
dist_ly = 3.39 ± 0.23 Mly (1.04 ± 0.07 Mpc)cite journal
author=I. D. Karachentsev, V. E. Karachentseva, W. K. Hutchmeier, D. I. Makarov
title=A Catalog of Neighboring Galaxies
journal=Astronomical Journal
year=2004
volume=127
pages=2031–2068
url=http://adsabs.harvard.edu/abs/2004AJ....127.2031K
doi=10.1086/382905] cite journal
author=Karachentsev, I. D.; Kashibadze, O. G.
title=Masses of the local group and of the M81 group estimated from distortions in the local velocity field
journal=Astrophysics
year=2006
volume=49
issue=1
pages=3–18
url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2006Ap.....49....3K
doi=10.1007/s10511-006-0002-6 ]
appmag_v = 15.5
size_v = 2′.9 × 2′.1
constellation name = Sagittarius
z = -79 ± 1 km/s
notes =
names = Sagittarius Dwarf Irregular, SGR Dwarf,
ESO594-G004, PGC 63287, Kowal's Object

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. citation
last1 = van den Bergh
first1 = Sidney
authorlink1 = Sidney van den Bergh
title = Updated Information on the Local Group
year = 2000
date = April 2000
journal = The Publications of the Astronomical Society of the Pacific
volume = 112
issue = 770
url = http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2000PASP..112..529V
pages = 529–536
doi = 10.1086/316548]

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 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 Gyr for the dominant population.citation
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
year = 2007
date = November 2007
journal = Astronomy and Astrophysics
volume = 475
issue = 2
url = http://adsabs.harvard.edu/abs/2007A%26A...475..467G
pages = 467–477
doi = 10.1051/0004-6361:20066848]

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