Ursa Minor

From Wikipedia, the free encyclopedia
  (Redirected from Ursa minor)
Jump to: navigation, search
Ursa Minor
Ursa Minor
Abbreviation UMi
Genitive Ursae Minoris
Pronunciation /ˌɜrsə ˈmnər/,
genitive /ˌɜrs mɨˈnɒrɨs/
Symbolism the lesser Bear
Right ascension 15
Declination +75
Family Ursa Major
Quadrant NQ3
Area 256 sq. deg. (56th)
Main stars 7
Stars with planets 1
Stars brighter than 3.00m 3
Stars within 10.00 pc (32.62 ly) 0
Brightest star Polaris (1.97m)
Nearest star UU UMi
(42.60 ly, 13.06 pc)
Messier objects 0
Meteor showers Ursids
Visible at latitudes between +90° and −10°.


Notable features[edit]

The constellation Ursa Minor as it can be seen by the naked eye.



The four stars constituting the "bowl" of the little dipper are unusual in that they are of second, third, fourth, and fifth magnitudes. Hence, they provide an easy guide to determining what magnitude stars are visible, useful for city dwellers or testing one's eyesight.

The six named stars of Ursa Minor are the following:

  Polaris (north star)      α UMi       2.02      430
  Kochab      β UMi       2.07      126
  Pherkad      γ UMi       3.00      480
  Yildun      δ UMi       4.85      185
  Ahfa al Farkadain      ζ UMi       4.32      376
  Anwar al Farkadain, Alasco      η UMi       4.95        97

Polaris (α UMi), the brightest star in the constellation, is a 'yellow-white' supergiant shining at 2.02 apparent magnitude . It belongs to the rare class of Cepheid variable stars. Kochab (β UMi) is only slightly less bright than Polaris. It is a 2.08 orange giant star, 16 degrees from Polaris. Kochab 126.4 ± 2.5 light years from the Sun, and is 130 times more luminous than the Sun, at a surface temperature of approximately 4,000 K.

Deep-sky objects[edit]

Ursa Minor is rather devoid of many deep-sky objects. A notable object is the Ursa Minor Dwarf, a dwarf galaxy, located in the area of the constellation.

Meteor showers[edit]

The Ursids are Ursa Minor's prominent meteor shower and peak between December 18 and 25. Its parent body is the comet 8P/Tuttle.[2]

History and mythology[edit]

Ursa Minor, with Draco looping around it, as depicted in Urania's Mirror,[3] a set of constellation cards published in London c.1825



Previously, Ursa Minor was considered just seven close stars, mythologically regarded as sisters. In early Greek mythology, the seven stars of the Little Dipper were the Hesperides, daughters of Atlas. Together with the nearby constellations of Boötes, Ursa Major, and Draco, it may have formed the origin of the myth of the apples of the Hesperides,[5] which forms part of the Labours of Hercules.[original research?] Ursa Minor with its modern associations was invented by Thales of Miletus in approximately 600 BCE, from what had previously represented the wings of Draco, the Dragon. He did so out of a desire to commemorate the location of the North Celestial Pole, then near Beta and Gamma Ursae Minoris.[6]

In Hungarian mythology the constellation is called 'Little Goncol cart' (Göncöl szekér) after a legendary shaman. (Ursa Major is 'Big Goncol cart.') The shaman's knowledge knew no limit. He invented the cart: His nation was wandering, so the cart was the biggest gift of the Gods to the country. Legends claim he knew everything about the world. Nobody saw his death; his body simply disappeared among the stars.


See also[edit]


  1. ^ Guilherme de Almeida (2004). Navigating the Night Sky: How to Identify the Stars and Constellations. Springer. ISBN 1-85233-737-0. 
  3. ^ "Urania’s Mirror c.1825 – Ian Ridpath's Old Star Atlases". Ianridpath.com. Retrieved 2012-02-13. 
  5. ^ "Draco Constellation". Constellation Guide. , Retrieved 2013-06-03.
  6. ^ Schaaf 2013.


External links[edit]

Coordinates: Sky map 15h 00m 00s, +75° 00′ 00″