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The Dubhe Star

The Ursa Major is a large sprawling constellation, the third largest in fact. It's mainly referred to as the home of the Big Dipper. It is certainly the best known asterism in all the heavens. This constellation offers a number of objects, some well known, others rather obscure, and one star that has been recently been in the news as having at least one temperate planet circling about it.

The Stars in the Ursa Major are as followed:
Alcor et Mizar

           The Dubhe Star is located on the upper right of the dipper on the Ursa Major. It is around 4 times bigger than that of the sun, and that about equal to 16 times the diameter. It has a temperature of 4500 Kelvins. The Luminosity Of Dubhe is 100, which is 100 times bright than that of the sun. It is classified in the K spectral Class.
           In the H-R Diagram its classified as a Main Sequence Star. The Star will eventually die when it runs out of hydrogen and then starts burning helium. When the helium runs out it will turn into a white dwarf. Then it will start to cool down and transform into a Black Dwarf.

           Here is the story of the Big Dipper.The "handle" of the dipper represents the "tail" of the bear on ancient star maps--even though modern bears don't have long tails! A Greek story (the Big Bear was so-called before Homer) explains that Zeus fell in love with a mortal woman named Callisto, who was a far-traveler and a huntress. His wife Hera became jealous, and changed Callisto into a large bear. When Callisto failed to return after a long journey, her son Arcas set out to find her, and in a forest one day met a huge bear. To his horror, the bear started to run toward him. Not perceiving it was his mother, Arcas fitted an arrow to his bow and was about to slay the bear, when Zeus, to avert the impending tragedy, changed Arcas into a smaller bear (he could not undo the spell of Hera). Then Zeus grabbed both bears by the tails, swung them around (thus stretching their tails out), and hurled them into the sky where they would be safe and immortal. However, Hera had the last word, moving them to the portion of the sky that never sets, so that until the end of the world Callisto and Arcas must endure weariness without rest.



The Star Dubhe Of The Ursa Major