lundi 29 septembre 2008

Pisces 12

α, Double and probably binary, 4 and 5.5, pale green and blue.

Al Rescha, or Al Rischa, derived from the Arabians' Al Rishāʼ, the Cord, is 20° south from the head of Aries, 2°.7 north of the celestial equator, and marks the knot in the united cords of the Fishes; the same title being applied to β Andromedae. this word originally may have come from the Babylonian Riksu, Cord.
Hipparchos and Ptolemy designated it as Σύνδεσμος τῶν Ἰχθύων, or τῶν Λίνων, the Knot of the Fishes, or of the Threads, varied by Aratos and Geminos in Δεσμός; these words being transcribed by Germanicus and the scholiasts as Sundesmos and Desmos. They were rendered by Cicero and others as Nodus, Nodus coelestis, and Nodus Piscium; but Pliny as Commissura Piscium; and in the 1515 Almagest as Nodus duorum filorum.
The Arabians translated these by ʽUḳd al Ḣaiṭain, which, as Okda and Kaitain, are not unusual titles now.
The uniting cords branching from α through ο, π, η, and ρ to the tail of the northernmost Fish, and through ξ, ν, μ, f, e, ζ, ε, and δ to ω that marks the tail of the one to the south, were Ptolemy's λίνον, "thread," the λίνοι of other authors. Cicero called them Vincla, the Bonds; and the scholiast on Germanicus, Alligamentum linteum or luteum, divided by Hevelius into Linum boreum and austrinum. Some of these terms also were applied to the star δ as marking one of the cords.
The Arabians knew these cords as Al Ḣaiṭ al Kattāniyy, the Flaxen Thread; and Al Aṣmaʽī, about the year 800, mentioned them in his celebrated romance Antarah as a distinct constellation; but Pliny had done the same long before him.
Al Rischa, though lettered first, is somewhat fainter than γ and η.
It culminates on the 7th of December.
The component stars are 3ʺ apart, at a position angle of 324°.
β, a 4 1/2‑magnitude, is given by Al Achsasi as Fum al Samakah, the Fish's Mouth, descriptive of its position near that feature in the westernmost of the two. With γ, θ, ι, and ω it was the Chinese Peih Leih, Lightning.
δ, 4.1,

has in Bayer's Uranometria many of the titles already noted under α, but they would seem to be words merely indicative of the star's position on the Cord, although some have used them as proper names. δ, α, ε, ζ, μ, ν, and ξ made up the Chinese figure Wae Ping, a Rolled Screen.
ζ, a double 5th- and 6.3‑magnitude, apparently unnamed, was prominent in Hindu astronomy as marking the initial point of the celestial sphere about the year 572, when it coincided within 10ʹ of longitude with the vernal equinox. It formed part of the Khorasmian lunar station Zidadh, the Sogdian Riwand, and of the 26th nakshatra, Revatī, Rich, being the junction star between Revatī and Açvini. With ε it was the Persian lunar station Kaht and the Coptic Kuton, Cord.

η, Double, 4 and 11.

Epping asserts that this marked the 1st ecliptic constellation of the Babylonians, Kullat Nūnu, the Cord of the Fish, which, if correct, would show the origin of the Greek title, and the probable great antiquity of the present figure. Another signification may be the Dwelling of the Fish.
In China, with ο, ρ, and χ, it was Yew Kang, the Right-hand Watch.
The components of η are 1ʺ apart, at a position angle of 12°.9.
κ and λ, 4th‑magnitude stars just above the ventral fin of the western Fish, were the Chinese Yun Yu, the Cloud and Rain.
ο, 4.6, appeared in the 1515 Almagest as Torcularis septentrionalis, a translation of ληνός, erroneously written for λίνος, this star being on the Thread northeast from α. But the Latin word should read Torcular.
Fl. 65, a 6th‑magnitude double, has been regarded by Maxwell Hall as the Central Sun of the Universe.

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