Orion 13

α, Irregularly variable, 0.7, orange.

Betelgeuze is from Ibṭ al Jauzah, the Armpit of the Central One; degenerated into Bed Elgueze, Beit Algueze, Bet El‑geuze, Beteigeuze, etc., down to the present title, which itself also is written Betelgeuse, Betelguese, Betelgueze, Betelgeux, etc. The Alfonsine Tables had Beldengenze, and Riccioli, Bectelgeuze and Bedalgeuze.
The star also was designated by various Arabian authors as Al Manib, the Shoulder; Al Dhirāʽ, the Arm; and Al Yad al Yamnāʼ, the Right Hand, — all of the Giant; but Chilmead wrote "Ied Algeuze, — that is, Orion's Hand," quoted from Christmannus.
The title Mirzam, from Al Murzim, the Roarer, or perhaps the Announcer, originally used for γ, also is applied to this as heralding the rising of its companions. La Lande, borrowing the full name of that star for this, quoted it as Almerzamo nnagied.
Sayce and Bosanquet identify α with the Euphratean Gula, other stars possibly being included under this title; and Brown says that Kakkab Sar, the Constellation of the king, or Ungal, refers to α with γ and λ. We can see in this signification the origin of the astrologer's idea that Betelgeuze portended fortune, martial honors, wealth, and other kingly attributes.
α alone constituted the 4th nakshatra, Ārdrā, Moist, depicted as a Gem, with Rudra, the storm-god, for its presiding divinity, and so, perhaps the origin of the long established stormy character of Orion. This lunar station, therefore, formed but a part of the 4th sieu, and differed entirely from the 4th manzil. Individually the star was the Sanskrit Bāhu, Arm, probably from the Hindu conception of the whole figure as a running Stag, or Antelope, of which α, β, γ, and κ marked the legs and feet, with α on the left forearm; the adjacent Sirius being the hunter Mrigavyadha.
Brown mentions its equivalent Persian title, Besn, the Arm, and the Coptic Klaria, an Armlet.
Bayer quoted γλήνεα from Aratos, but it is not in original; and Chrysococca had Ὤμος διδύμων, the Shoulder of — i.e. next to — the Twins.
Among the many queerly worded descriptions in the 1515 Almagest, perhaps none in more so than that of this star, reading in part thus: ipsa tendit ad rapinam quae appropinquat ad terram. This tendit ad rapinam, also used for the star Antares, apparently has been an unsolved puzzle; and as I have never seen any explanation, my own suggestion may not be amiss. The 1515 Almagest followed Ulug Beg's Tables, and these followed Ptolemy, who characterized the color of α as ὑπόκιρρος, which Ulug Beg's translation turned into rubedinem, "ruddiness," and the Almagest into the not very different word of the quotation, expressing ideas of war and carnage, astrology's attributes of red stars. The appropinquat ad terram doubtless refers to the comparatively elevation of the star above the horizon. See Allen's alternate explanation, in connection with Antares, s.v. Scorpio.
Professor Young says that at times, when near a minimum, it closely matches Aldebaran in color and brightness, and Lassell described it as a rich topaz. Secchi makes it the typical star of his third class with a banded spectrum, suggesting that it may be approaching the point of extinction. Elkin finds its parallax insensible; according to Vogel, it is receding from the earth at the rate of 10 1/2 miles a second.
It was first seen to be variable by Sir John Herschel in 1836, from which time till 1840 "its variations were most marked and striking." A similar period began in 1849, and on the 5th of December, 1852, "it was actually the largest star in the northern hemisphere." It was especially brilliant in 1894. Argelander found a period of 196 days, but Schoenfeld thought periodicity questionable.
Its position is less than 3° west of the solstitial colure; it rises at sunset on the 30th of December, and culminates on the 29th of January. It has an 8th‑magnitude companion 20ʹ away, first observed by Wilhelm Struve as double, 18ʺ.5 apart, and the great glasses of the present day reveal other members in combination still nearer and smaller than the original companion; while Barnard has discovered about it large and diffused nebulosity.

β, Double, 0.3 and 8, both bluish white.

Algebar and Elgebar are seen in poetry for the star, but it universally is known as Rigel, from Rijl Jauzah al Yusrāʽ, the Left Leg of the Jauzah, by which extended title the Arabians knew it after the word Jauzah had become a personal title; the modern name first appearing in the Alfonsine Tables of 1521. These say of it, in connection with Eridanus:
Lucida que est in pede sinistro: et est communis ei et aquae: et dicitur Algebar nominatur etiam Rigel.
Riccioli had Regel; Schikard, Riglon; and Chilmead, Rigel Algeuze, or Algibbar.
Al Sufi gave the earlier popular name Rāʽi al Jauzah, the Herdsman of the Jauzah, whose camels were the stars α, γ, δ and κ; and Al Najīd, the Conqueror, which also was given to α and γ.
Chrysococca termed it Πούς δίδυμων, the Foot of — i.e. next to — the Twins; and Bayer, the Hebrew Kesil, of the constellation.
Smyth wrote that
independent of the "nautis infestus Orion" character of the constellation, Rigel had one of his own; for it was to the astronomical rising of this "marinus aster," in March, that St. Marinus and St. Aster owe their births in the Romish calendar.
He gave, however, no explanation of this, and these saints certainly are not familiar in any stellar connection. Possibly its "marine" character came from its location at the end of the River, and from its being given in the various editions of the Syntaxis and in the Alfonsine Tables as common p313to both constellations; although the supposed stormy character of the whole group in affecting navigation may have induced the epithet for Orion's greatest star.
Astrologers said that splendor and honors fell to the lot of those who were born under it.
In the Norsemen's astronomy Rigel marked one of the great toes of Orwandil, the other toe having been broken off by the god Thor when frost-bitten, and thrown to the northern sky, where it became the little Alcor of the Greater Bear.
Although lettered below Betelgeuze, it is usually superior to it in brightness, being estimated in the Harvard Photometry as exactly equal to Arcturus, Capella, and Wega. Its spectrum is like that of Sirius, and it is receding from our system about 10 1/4 miles a second.
The smaller star, at a position angle of 200°, is 9ʺ.1 away, but not easily seen owing to the brightness of the principal. It is strongly suspected that this smaller star itself is closely double.
Another minute companion is 44ʺ.5 away.