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UMa
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Ursae Majoris
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the Great Bear
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1067
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5538
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1280
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3rd
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6
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&epsilon UMa (Alioth)
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17
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"http://wwwinformationdelightinfo/encyclopedia/entry/Leonids-Ursids" class="copylinks">Leonids-Ursids
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"http://wwwinformationdelightinfo/encyclopedia/entry/Boötes" class="copylinks">Boötes
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90
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30
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April
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(Ursa Maior in
Latin ) is a
Constellation visible throughout the year in the northern hemisphere. Its name means ''
Great Bear '' in
Latin , and is associated with the legend of
Callisto .
The seven brightest
Star s, located in the Bear's hindquarters and tail, form the well-known
Asterism . (In
Britain , this asterism is known as the Plough.) Except for Dubhe and Alkaid, the stars of the Big Dipper all have
Proper Motion s 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 Star s, 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 .
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. Other galaxies in Ursa Major that appear in the Messier catalogue are
M108 and
M109 , both spiral galaxies. All told, the constellation contains about 50 galaxies observable through
Telescope s available to the
Amateur Astronomer , most of which are below 10th magnitude. 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.
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 .
The constellation of Ursa Major has been seen by many distinct civilizations as a bear. In consequence, 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.
One of the few star groups mentioned in the 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.)
Source:
The Bright Star Catalogue, 5th Revised Ed.,
The Hipparcos Catalogue, ESA SP-1200
