mercredi 1 octobre 2008

Corvus 7

α, 4.3, orange.

Al Chiba is from the Desert title for the whole Arabic figure; but Ulug Beg and the Arabian astronomers designated it as Al Minḣar al Ghurāb, the Raven's Beak.
Reeves said that it was the Chinese Yew Hea, the Right-hand Linch-pin.
Although lettered first, it now is so much less brilliant than the four following p182stars that some consider it as having decreased since Bayer's day, and perhaps changed in color, for Al Sufi called it red.
β, a ruddy yellow 3d‑magnitude star, seems unnamed except in China, where it is Tso Hea, the Left-hand Linch-pin; but under this title were included γ, δ, and η.

γ, 2.3.

Gienah is from Ulug Beg's Al Janāḥ al Ghurāb al Aiman, the Right Wing of the Raven, although on modern charts it marks the left. Algorab, given in the Alfonsine Tables to this star, is now usually applied to δ.
γ is the brightest member of the constellation, and some Chinese authorities said that it alone marked their 11th sieu. It culminates on the 10th of May.
δ, Double 3.1 and 8.5, pale yellow and purple.
Algorab, the generally received modern title, is from the Palermo Catalogue; Proctor has Algores. It is on the right wing, and at the upper left corner of the square. The components are 24ʺ apart; but, owing to its color, the smaller is not readily distinguishable. The position angle is 210°.
All the foregoing stars, ε being added, constituted the 11th nakshatra, Hasta, the Hand, with Savitar, the Sun, as its presiding divinity; δ marking the junction with Citrā, the next lunar station.
The 11th sieu, Tchin, the Cross-piece of a chariot, anciently Kusam, contained β, γ, δ, and ε; but, according to some authorities, only γ. This, however, always was the determining star.
ζ, a 6th‑magnitude double, almost on the limit of invisibility, strangely seems to have borne a name in China, — Chang Sha, a Long Sand-bank.
Al Bīrūnī said that with β, γ, and δ it marked the hind quarters of the monstrous early Lion.

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