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Ursa Major - the Great Bear


Mythology - This area of sky has been depicted as a bear in many cultures across the globe prompting certain ethnologists to think that one Siberian tribe migrated down into North America, Europe and China carrying their story with them. According to the Greeks it represents Callisto, a beautiful nymph seduced by Zeus. She gave birth to a son, Arcas, a great hunter. When Hera found out she turned Callisto into a bear and later on Arcas was about to shoot her in ignorance. Out of pity, Zeus turned Arcas into a bear before he could kill his mother and threw both animals into the sky by their tails, thus stretching them out. Various native American tribes have bear stories, notably the Algonquin and Iroquois, where the bear is being pursued by hunters represented by the bright stars we know as the handle of the Plough and Boötes. The seven brightest stars of the bear are known in the UK as The Plough or the Saucepan, in France as le Casserole, the Big Dipper in USA and in Reformation Britain as Charle's Wain or wagon (carried by him to his execution). Older Wiltshire folk still refer to it as Jack's Wain, where Jack is the star Alcor. King Arthur was named from Arth meaning "bear" and Uther meaning "luminous" - a direct link to this constellation in Celtic times.
Stars - The Plough hosts the most famous double star, Alcor and Mizar, known as the horse and rider by native Americans. This optical double used to be a test of eyesight in the Roman army. These are not gravitationally bound, but Mizar itself is a true double when seen through a modest telescope.
Deepsky - Just below the blade of the Plough is a planetary nebula - M97, or the Owl Nebula. This ghostly disk can be glimpsed with a modest telescope, but to see the two dark patches or “eyes” requires a 12”
instrument or larger. Ursa Major is the site of some interesting galaxies, most notably M81 and M82 which are both fairly is the site of some interesting galaxies, most notably M81 and M82 which are both fairly nearby in galactic terms. M81 is a beautiful spiral, whilst M82 is an active, irregular galaxy. Both are visible in 10 x 50 binoculars on a dark night. M101 above the handle of the Plough is a fairly faint, face-on
spiral famous for producing supernovæ (three this century).
Visibility - Although visible all year round, the best time to see the Great Bear is in Spring when he lies directly overhead.