dimanche 5 octobre 2008

Pegasus 10

δ, 2.2, white.

This, as already noted, is the same as Alpheratz (α Andromedae), and recognized by astronomers of every age as in either constellation; or, as Aratos wrote, ξυνός ἀστήρ, "a common star." It seems to be unnamed as a member of Pegasus.
Al Achsasi included it with γ in the Fargh al Muʼḥir.
ε, Triple, 2.5, 11.5, and 8.8, yellow, , and blue.

Enif, Enf, and Enir, all titles for this, are from Al Anf, the Nose, by which the Arabians designated it. Scaliger had Enf Alpharas, and Schickard Aniphol Pharasi. It was also Fum al Faras, the Horse's Mouth; and Al Jaḥfalah, the Lip, this last being found on one of their globes.
Bayer quoted from "the interpreters of the Almagest" Grumium and Muscida, respectively Jaw and Muzzle, so describing its position; but these have become proper names for ξ Draconis and π Ursae Majoris. Flamsteed knew it as Os Pegasi.
With θ, and the star α Aquarii, it was the 23d sieu, Goei, or Wei, Steep or Danger, anciently Gui.
Enif's spectrum is Solar, and it is receding from us about five miles a second. Gould thinks it probably variable.
ζ, 3.7, light yellow.

Homam seems to have been first given to this in the Palermo Catalogue, from Saʽd, This Arabic Saʽd is our "Good Luck" and a component word of many titles in the Desert sky, all of which seem to have been applied to stars rising in the morning twilight at the commencement of the pleasant season of spring. Al Saʽdain, the dual form, was the title for Jupiter and Venus, the Two Fortunate Planets; Al Nahsān, the Unlucky, referring to Mars and Saturn, al Humām, the Lucky Star of the Hero, in which Ulug Beg included ξ; other lists have Homan. But Hyde said that the original was Al Hammām, Whisperer. Al Tizini mentioned it as Saʽd al Naʽamah, the Lucky Star of the Ostriches; and Al Achsasi, as Nāʼir Saʽd al Bahāim, the Bright Fortunate One of the Two Beasts, which Al Sufi had said were θ and ν. Thus ξ was one of the general group Al Suʽūd al Nujūm, the Fortunate Stars.
The Chinese called it Luy Tien, Thunder.
7° to the north of ζ is the point assigned by Denning as the radiant of the first stream of Pegasids, the meteors visible about the 28th of June; although Espin locates it near δ Cygni.
η, Double, 3.2,

on the left forearm, is the Matar of Whitall's Planisphere, from Al Saʽd al Maṭar, the Fortunate Rain; as such, however, ο was included with it.
θ, 3.8, and ν, 4.8,

were Al Sufi's Saʽd al Bahāim, the Good Luck of the Two Beasts; Al Achsasi adding to the group the still brighter ζ. θ alone is Baham in some modern lists; but Ulug Beg had Bihām, the Young of domestic animals.
It appears on the Dresden globe as Al Ḥawāʼim, the Thirsty Camels.

κ, Triple and binary, 4.8. 5.3, and 10.8, yellowish and orange,

marking the right forearm, is unnamed except in China, where it is Jih, the Sun, a title also for κ and λ Librae.
The two largest stars were divided by Burnham in 1880 and found to be 0ʺ.2 apart, this decreasing to 0ʺ.1 in 1891. Their orbital period of revolution is 11 1/2 years, and, with that of δ Equulei, the most rapid known to astronomers until See discovered the binary character of Ll. 9091 in Orion. The first and third stars are 11ʺ apart, at a position angle of 308°.5.
λ, 4.1, and μ, 3.4,

were Saʽd al Bārīʽ, the Good Luck of the Excelling One; but Kazwini designated it as Saʽd al Nāziʽ, the Good Luck of the Camel Striving to Get to Pasture.
p329 ν was Fum al Faras and Al Jaḥfalah, but both titles are more correctly applied to ε.
π was the Chinese Woo, a Pestle.

τ, 4.5,

with υ, was Al Sufi's Saʽd al Naʽamah, which Knobel thinks should be Al Naʽāim, the Cross-bars over a well; but they also were known as Al Karab, the Bucket-rope.
The usual titles for τ — Markab and Sagma or Salma — are from Bayer, but the last two should be Salm, a Leathern Bucket.
λ μ, η ο, and υ τ, forming a group of three pairs, were a noted asterism in Chian, under the title Li Kung.
This long list of names for rather inconspicuous stars shows unusual early interest in the constellation.

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