Ursa Major

This article is about the Great Bear constellation. For other uses of The Great Bear, see Great Bear.

Ursa major
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Abbreviation	UMa
Genitive	Ursae Majoris
Symbology	the Great Bear
Right ascension	10.67 h
Declination	55.38°
Area	1280 sq. deg. Ranked 3rd
Number of stars (Bayer-Flamsteed)	80
Number of bright stars (magnitude < 3)	6
Number of nearby stars (Distance < 100 ly)	14
Brightest star	ε UMa (Alioth) (App. magnitude 1.7)
Nearest Star	ξ UMa (Alula Australis) (Distance: 28.8 ly)
Meteor showers	Alpha Ursa Majorids Leonids-Ursids
Bordering constellations	Draco Camelopardalis Lynx Leo Minor Leo Coma Berenices Canes Venatici Boötes
Visible at latitudes between +90° and −30° Best visible at 21:00 (9 p.m.) during the month of April
The Big Dipper

Ursa Major (IPA: /ˈəːsə ˈmeɪdʒə/) is a constellation visible throughout the year in most of the northern hemisphere. Its name means Great Bear in Latin, and is associated with the legend of Callisto.

Notable features

The seven brightest stars, located in the Bear's hindquarters and tail, form the well-known Big Dipper asterism. (In Britain, this asterism is known as the Plough.) Except for Dubhe and Alkaid, the stars of the Big Dipper all have proper motions heading towards a common point in Sagittarius. A few other such stars have been identified, and together they are called the Ursa Major Moving Group.

In addition to the Big Dipper, another asterism comes from Arab culture – the "leaps of the gazelle", a series of three pairs of stars:

• ν and ξ Ursae Majoris, Alula Borealis and Australis, the "first leap";
• λ and μ Ursae Majoris, Tania Borealis and Australis, the "second leap";
• ι and κ Ursae Majoris, Talitha Borealis and Australis, the "third leap".

These stars are found along the southwest border of the constellation, the bear's toes.

W Ursae Majoris is the prototype of a class of contact binary variable stars, and ranges in magnitude between 7.75m and 8.48m.

47 Ursae Majoris has a planetary system with two confirmed planets, 2.54 times and 0.76 times the mass of Jupiter.

Notable deep sky objects

Several bright galaxies are found in Ursa Major, including the pair M81 (one of the brightest galaxies in the sky) and M82 above the bear's head, and M101, a beautiful spiral northwest of η Ursae Majoris. The notable spiral galaxies M108 and M109 may also be found in this constellation. Altogether, the constellation contains about 50 galaxies observable through amateur telescope. The bright planetary nebula M97, also known as the "Owl Nebula" for its appearance in photographs, can be found along the bottom of the bowl of the Big Dipper. Of note as a curiosity more than an interesting deep sky object is M40, a double star that Messier nonetheless included in his catalogue.

The Hubble Deep Field is located to the northeast of δ UMa.

History

The drawing Hevelius made of Ursa Major. The drawing is made as if being viewed from outside the celestial sphere.

Ursa Major was one of the 48 constellations listed by Ptolemy. It is one of the most widely-known constellations, having been mentioned by such poets as Homer, Spenser, Shakespeare, Tennyson and Bertrand Cantat. The Finnish epic Kalevala mentions it, and Vincent Van Gogh included its stars in his Starry Night Over the Rhone.

Mythology

The constellation of Ursa Major has been seen by many distinct civilizations as a bear.^[1] In one sequence, together with the nearby Ursa Minor, it formed the basis of the myth of Callisto.

In earlier times, Greek mythology did not consider Ursa Major a bear, and instead its 3 bright stars (situated in the tail) were seen as apples growing on a tree (sometimes represented by the fainter stars in the remainder of the constellation). At the same time, the stars of Ursa Minor were associated with the Hesperides. These two groups of stars, together with Libra, Boötes and Draco, may have inspired the myth of the apples of the Hesperides, one of The Twelve Labours of Hercules. In Hindu mythology the seven stars are identified with seven sages and the constellation is called Saptarshi Mandalam.

One of the few star groups mentioned in the Bible (Job 9:9; 38:32 – Orion and the Pleiades being others), Ursa Major was also pictured as a bear by both the Hebrews and most North American peoples. However, as bears do not have long tails, they considered Alioth, Mizar, and Alkaid to be either three cubs following their mother or three hunters. ("The Bear" was mistranslated as "Arcturus" in the Vulgate and the error persisted in the KJV. Later translations have corrected this.)

The Iroquois Native Americans also interpreted Alioth, Mizar, and Alkaid as three hunters pursuing the Great Bear. According to one version of their myth, the first hunter (Alioth) is carrying a bow and arrow to strike down the bear. The second hunter (Mizar) carries a large pot on his shoulder in which to cook the bear while the third hunter (Alkaid) hauls a pile of firewood to light a fire beneath the pot.

In Burmese, Pucwan Tārā (pronounced "bazun taja") is the name of a constellation comprising stars from the head and forelegs of Ursa Major; pucwan is a general term for prawn, shrimp, crab, lobster, etc.

Graphic Visualisation

Trivia

• Ursa Major was said to be the location of a massive black hole in the British cult-horror series Children of the Stones.
• The Flag of Alaska consists of eight gold stars, forming the Big Dipper part of Ursa Major and Polaris, The North Star, on a dark blue field. It was designed in 1927 by Benny Benson, a 13-year-old Alaska Native residing in Seward, for a contest to create a flag for the then-Alaska Territory.
• Ruuko Kireinasora, a character from ToHeart2, comes from the third planet of Ursa Major 47.

Notable and named stars

Source: The Bright Star Catalogue, 5th Revised Ed., The Hipparcos Catalogue, ESA SP-1200

See also

• Ursa Major Moving Group

Notes

1. ^ Gibbon, William B. "Asiatic parallels in North American star lore: Ursa Major" in the Journal of American Folklore. 77(305), 236–250, July 1964.

External links

• The Deep Photographic Guide to the Constellations: Ursa Major
• AAVSO: The Myths of Ursa Major
• The Origin of the Greek Constellations

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