Ursa Minor Dwarf
{{Short description|Dwarf spheroidal galaxy}}
{{Infobox Galaxy
| image =Ursa Minor Dwarf - Giuseppe Donatiello.jpg
| caption = Ursa Minor Dwarf
| name = Ursa Minor Dwarf
| epoch = J2000
| type = E{{cite web
| title=NASA/IPAC Extragalactic Database
| work=Results for Ursa Minor Dwarf
| url=http://nedwww.ipac.caltech.edu/
| access-date=2006-11-29 }}
| dist_ly = 200 ± 30 kly (60 ± 10 kpc){{cite journal
| author=I. D. Karachentsev
| author2=V. E. Karachentseva
| author3=W. K. Hutchmeier
| author4=D. I. Makarov
| 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
| author=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
}}
| constellation name = Ursa Minor
| notes = Satellite galaxy of Milky Way
| names = UGC 9749, PGC 54074, DDO 199, UMi Dwarf }}
File:Ursa-Minor-Dwarf-Combi-image-text.jpg
The Ursa Minor Dwarf is a dwarf spheroidal galaxy, discovered by A.G. Wilson of the Lowell Observatory, in the United States, during the Palomar Sky Survey in 1955.{{cite book|last=Bergh|first=Sidney |title=The Galaxies of the Local Group|publisher=Cambridge University Press|location=Cambridge, United Kingdom|date=2000|pages=257|isbn=978-1-139-42965-8|url=https://books.google.com/books?id=H0JMeoqFqEcC&pg=PA257}} It appears in the Ursa Minor constellation, and is a satellite galaxy of the Milky Way. The galaxy consists mainly of older stars and seems to house little to no ongoing star formation. Its centre is around 225,000 light years distant from Earth.{{cite journal|author=Grebel, Eva K.|author2=Gallagher, John S., III|author3=Harbeck, Daniel|title=The Progenitors of Dwarf Spheroidal Galaxies|journal=The Astronomical Journal|year=2003|volume=125|issue=4|pages=1926–39|doi=10.1086/368363 | bibcode=2003AJ....125.1926G|arxiv = astro-ph/0301025 |s2cid=18496644}}
Evolutionary history
In 1999, Kenneth Mighell and Christopher Burke used the Hubble Space Telescope to confirm that the Ursa Minor dwarf galaxy had a straightforward evolutionary history with a single burst of star formation that lasted around 2 billion years and took place around 14 billion years ago,{{Cite journal | last1 = van den Bergh | first1 = Sidney | author-link1 = 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 = 529–36 | doi = 10.1086/316548 |arxiv = astro-ph/0001040 | s2cid = 1805423 }} and that the galaxy was probably as old as the Milky Way itself.{{cite journal|author=Mighell, Kenneth J.|author2=Burke, Christopher J.|date=1999|title=WFPC2 Observations of the Ursa Minor Dwarf Spheroidal Galaxy|journal=The Astronomical Journal|volume=118|issue=366|pages=366–380|doi=10.1086/300923|arxiv = astro-ph/9903065 |bibcode = 1999AJ....118..366M |s2cid=119085245}}
See also
References
{{reflist}}
External links
- {{commonscat-inline}}
- {{WikiSky|name=The Ursa Minor Dwarf}}
{{Milky Way}}
{{Sky|15|09|08.5|+|67|13|21|200000}}