mardi 23 septembre 2008

Perseus 5


Alpha Persei (α Per) is the brightest star in the constellation of Perseus, just outshining the constellation's best known star Algol. It also bears the traditional names of Mirfak or Algenib. A yellow-white supergiant, it lies around 590 light years from Earth and is a member of a cluster of stars known as the Alpha Persei Cluster.

The names Mirfak and Algenib are Arabic in origin. The former, meaning 'Elbow' and also written Mirphak, Marfak or Mirzac, comes from the Arabic Mirfaq al-Thurayya, while Algenib, also spelt Algeneb, Elgenab, Gęnib, Chenib or Alchemb, is derived from الجنب al-janb, or الجانب al-jānib, 'the flank' or 'side'. Gamma Pegasi also bears the name Algenib.
It forms part of Tien Yuen, the Heavenly Enclosure, in traditional Chinese astronomy.
Hinali'i is the name of the star in Native Hawaiian astronomy. The name of the star is meant to commemorate a great tsunami and mark the beginning of the migration of Maui. According to some Hawaiian folklore, Hinali'i is the point of separation between the earth and the sky that happened during the creation of the Milky Way.
The star Hinali'i first rises in the east in the month of August and follows the path of another star, probably α, β and γ Cassiopeiae.


Algol (β Per / Beta Persei), known colloquially as the Demon Star, is a bright star in the constellation Perseus. It is one of the best known eclipsing binaries, the first such star to be discovered, and also one of the first (non-nova) variable stars to be discovered. Algol is actually a three-star system (Beta Persei A, B and C) in which the large and bright primary Beta Persei A is regularly eclipsed by the dimmer Beta Persei B. Thus, Algol's magnitude is usually near-constant at 2.1, but regularly dips to 3.4 every 2 days, 20 hours and 49 minutes during the roughly 10-hour long partial eclipses. There is also a secondary eclipse when the brighter star occults the fainter secondary. This secondary eclipse can only be detected photoelectrically.[

The name Algol derives from Arabic رأس الغول ra's al-ghūl : head (ra's) of the ogre (al-ghūl) (see "the ghoul") which was probably given due to its peculiar behavior. The English names of Demon Star and Blinking Demon are direct translations. In Hebrew folklore it was known as Rōsh ha Sāṭān 'Satan's Head', via Edmund Chilmead, who called it 'Divels head' or Rosch hassatan. A Latin term from the 16th century was Caput Larvae 'Spectre's Head'. It was also linked with Lilith.[14] In the constellation Perseus, it represents the eye of the Gorgon Medusa. Hipparchus and Pliny made this a separate, though connected, constellation.
It is known as 大陵五 (the Fifth Star of the Mausoleum) in Chinese astronomy, and also bore the grim name Tseih She (叠尸 - die2 shi1 in Modern Pinyin), meaning 'Piled up corpses'.

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