Ursa Minor Dwarf Galaxy

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Galaxy
Ursa Minor Dwarf Galaxy
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Ursa Minor Dwarf - Giuseppe Donatiello.jpg
AladinLite
Constellation Little Bear
Position
equinox :  J2000.0 , epoch : J2000.0
Right ascension 15 h 09 m 08.5 s
declination + 67 ° 13 ′ 21 ″
Appearance
Morphological type dE / dSph  
Brightness  (visual) 11.9 likes
Angular expansion 30.2 'x 19.1'
Physical data
Affiliation Local group  
Radial velocity (-247 ± 1) km / s  
distance (240 ± 36) * 10³ ly /
(73 ± 11) * 10³ pc
Metallicity [Fe / H] [Fe / H] ˜ -2
history
discovery Albert George Wilson
Discovery date 1954
Catalog names
UGC  9749 • PGC  54074 • CGCG  318-018, 319-001 • MCG  + 11-18-30 • DDO 199

The Ursa Minor Dwarf Galaxy is an elliptical dwarf galaxy in the constellation of the Little Bear . It was discovered in 1954 by Albert George Wilson at the Lowell Observatory and is a satellite of the Milky Way .

properties

The galaxy consists mainly of an older star population and shows little to no current star formation . In 1999 the astrophysicists Kenneth Mighell and Christopher Burke were able to show with the help of the Hubble Space Telescope that only a single star formation phase took place in the Ursa Minor dwarf galaxy up to about 11 billion years ago, which lasted about 2 billion years.

See also

Individual evidence

  1. ↑ a b c d e NASA / IPAC Extragalactic Database
  2. ↑ Karachentsev, ID; Kashibadze, OG: Masses of the local group and of the M81 group estimated from distortions in the local velocity field . In: Astrophysics . 49, No. 1, 2006, pp. 3-18. bibcode : 2006Ap ..... 49 .... 3K . doi : 10.1007 / s10511-006-0002-6 .
  3. ^ Sidney van den Bergh : Updated Information on the Local Group . In: The Publications of the Astronomical Society of the Pacific . 112, No. 770, April 2000, pp. 529-536. arxiv : astro-ph / 0001040 . bibcode : 2000PASP..112..529V . doi : 10.1086 / 316548 .
  4. ↑ Kenneth J. Mighell, Christopher J. Burke: WFPC2 Observations of the Ursa Minor Dwarf Spheroidal Galaxy . In: Astronomical Journal . 118, No. 770, March 1st, pp. 366-380. arxiv : astro-ph / 9903065 . bibcode : 2000PASP..112..529V . doi : 10.1086 / 300923 .

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