Voyager . . .

Tuesday, June 5, 2018

The Nautical Almanac # 34 --- Alkaid, the Eldest Daughter (Cauda Ursar, the Bear's Tail)


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The 34th star in the Nautical Almanac is Alkaid (Eta Ursae Majoris) the tail-end star in the handle of the Big Dipper (Ursa Major, The Great Bear). 

The name "Alkaid" is contracted Arabic for "The Eldest Daughter" (a rough translation) and in Arabic astrology Alkaid, Mizar and Alioth the three stars of the handle are called "The Mourning Maidens." The four stars of the bowl are called "The Bier," and the asterism represents a funeral procession in the sky. According to the mythology, the three daughters were the children of Al Na'ash, who was murdered by Al Jadi, represented by the pole-star (Polaris), and they are still circling around him, demanding vengeance. The murder may have been justified however, since the young women are elsewhere referred to as "good for nothing people."

The Spanish word Alcalde ("Leader" but today usually translated "Mayor") is derived from Alkaid.
In Chinese astrology it is known as "The Revolving Star" (it revolves around Polaris), "Brilliant and Twinkling," or simply "The Seventh Star." The people of India saw Alkaid as one of "The Seven Wise Men (Rishis)." The Dipper as a whole has been seen as an Oxcart, a Plough, a Wagon, or a Scythe, and Alkaid always has a prominent role in these stories. 

Alkaid is one of the fifteen Behenian stars and in Hermetic astrology (under the name Cauda Ursar or "The Tail of the Bear") grants protection to travelers and safety against enchantments. 

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Alkaid lies above the galactic plane; we do not look "out" at it as much as "up." It (along with Dubhe) is moving away from the other stars of the Dipper, and slowly elongating its shape.

Alkaid lies 105 light years away from Earth. It is a second magnitude star, a blue dwarf, which burns at a surprisingly low temperature (for a blue star) of 28,000 degrees F. 

Alkaid is a young ten million years old. It is 594 times as luminous as the Sun. It has six times the mass and three-and-one-half times the radius of the Sun. It emits vast amounts of X-Rays. Earth would have to be in a Neptunian orbit if life were to survive here with Alkaid as our home star.

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