Dwarf spheroidal galaxy
Amateur image, 10.7 hr. exposure with Esprit 100 APO Refractor+QHY16200CCD @-20C/ IDAS LP2 filter.
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.[ 4] 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 .[ 5]
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,[ 6] and that the galaxy was probably as old as the Milky Way itself.[ 7]
See also
References
^ a b c d e f g h i j "NASA/IPAC Extragalactic Database" . Results for Ursa Minor Dwarf . Retrieved 2006-11-29 .
^ I. D. Karachentsev; V. E. Karachentseva; W. K. Hutchmeier; D. I. Makarov (2004). "A Catalog of Neighboring Galaxies" . Astronomical Journal . 127 (4): 2031–2068. Bibcode :2004AJ....127.2031K . doi :10.1086/382905 .
^ 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. Bibcode :2006Ap.....49....3K . doi :10.1007/s10511-006-0002-6 . S2CID 120973010 .
^ Bergh, Sidney (2000). The Galaxies of the Local Group . Cambridge, United Kingdom: Cambridge University Press . p. 257. ISBN 978-1-139-42965-8 .
^ Grebel, Eva K.; Gallagher, John S., III; Harbeck, Daniel (2003). "The Progenitors of Dwarf Spheroidal Galaxies". The Astronomical Journal . 125 (4): 1926–39. arXiv :astro-ph/0301025 . Bibcode :2003AJ....125.1926G . doi :10.1086/368363 . S2CID 18496644 . {{cite journal }}
: CS1 maint: multiple names: authors list (link )
^ van den Bergh, Sidney (April 2000). "Updated Information on the Local Group". The Publications of the Astronomical Society of the Pacific . 112 (770): 529–36. arXiv :astro-ph/0001040 . Bibcode :2000PASP..112..529V . doi :10.1086/316548 . S2CID 1805423 .
^ Mighell, Kenneth J.; Burke, Christopher J. (1999). "WFPC2 Observations of the Ursa Minor Dwarf Spheroidal Galaxy". The Astronomical Journal . 118 (366): 366–380. arXiv :astro-ph/9903065 . Bibcode :1999AJ....118..366M . doi :10.1086/300923 . S2CID 119085245 .
External links