Richard H. Allen comenta sobre Cygnus

Those deathless odalisques of heaven's hareem,
The Stars, unveil; a lonely cloud is roll'd
Past by the wind, as bears an azure stream
A sleeping swan's white plumage fringed with gold.
Adam Mickiewicz' Polish Evening Hymn.

Cygnus, the Swan,

that modern criticism says should be Cycnus, lies between Draco and Pegasus. The French know it as Cygne; the Italians as Cigno; the Spaniards as Cisne; and the Germans as Schwan.
It was Κύκνος with Eratosthenes, but usually Ὄρνις with other Greeks, by which was simply intended a Bird of some kind, more particularly aHen; although the ἀιόλος of Aratos may indicate that he had in view the "quickly flying swan"; but, as this Greek adjective also signifies "varied," it is possible that reference was here made to the Bird's position in the Milky Way, in the light and shade of that great circle. With this idea, Brown renders it "spangled." Aratos also described it as ἠρόεις, "dark," especially as to its wings, an error which Hipparchos corrected.
When the Romans adopted the title that we now have, our constellation became the mythical swan identified with Cycnus, the son of Mars, or of the Ligurian Sthenelus; or the brother of Phaëthon, transformed at the river p193Padus and transported to the sky.1 Associated, too, with Leda, the friend of Jupiter and mother of Castor, Pollux, and Helena, it was classed among the Argonautic constellations, and Helenae Genitor, with other names derived from the well-known legend, was applied to it.
Popularly the constellation was AlesAvis, and Volucris, a Bird, — Alea JovisAles Ledaeus, and Avis Veneris, — while Olor, another word for the Swan, both ornithological and stellar, has been current even to modern times. Phoebi Assessor is cited by La Lande, the bird being sacred to that deity; and Vultur cadens is found for it, but this was properly Lyra's title. As the bird of Venus it also has been known as Myrtilus, from the myrtle sacred to that goddess; and it was considered to be Orpheus, placed after death in the heavens, near to his favorite Lyre.
Our Cygnus may have originated on the Euphrates, for the tablets show a stellar bird of some kind, perhaps Urakhga, the original of the Arabs'Rukh, the Roc, that Sindbad the Sailor knew. At all events, its present figuring did not originate with the Greeks, for the history of the constellation had been entirely lost to them, as had that of the mysterious Engonasin (Hercules), — an evident proof that they were not the inventors of at least some of the star-groups attributed to them.
In Arabia, although occasionally known as Al Ṭā’ir al Ardūf, the Flying Eagle, Chilmead's Altayr, or as Al Radīf, it usually was Al Dajājah, the Hen, and appears as such even with the Egyptian priest Manetho, about 300 B.C., this degenerating into the AdigeAdigegeAldigaga,AddigagatoDegigeEdegiagithEldigiagich, etc., of early lists, some of these even now applied to its brightest star.
Scaliger's Al Ridhadh, for the constellation, which degenerated to El Rided, perhaps is the origin of our Arided for the lucida (Alpha star, Deneb Adige), but its signification is uncertain, although the word is said to have been found in an old Latin-Spanish-Arabic dictionary for some sweet-scented flower.
Hyde gives Kathā for it, the Arabic Al Kaṭāt, a bird in form and size like a pigeon; indeed, Al Sufi's translator, Schjellerup, defined the latter's title for it, Al Ṭā’ir, as le pigeon de poste; but Al Kaṭāt is now the Arabs' word for a common gallinaceous game-bird of the desert, perhaps the mottled partridge.
The Alfonsine Tables, in the recent Madrid edition, supposed to be a reproduction of the original, illustrate their Galina by a forlorn Hen instead p194of a Swan, with the bungled Arabic title altayr aldigeya, although elsewhere they say Olor: Hyparcus Cygnum vocat; the Arabo-Latin Almagestof 1515 had Eurisim: et est volans; et jam vocatur gallina. et dicitur eurisim quasi redolens ut lilium ab ireo; the Alfonsine Tables of 1521 haveHyresym; et dicitur quasi reddens ut lilium: et est volans: et jam vocatur gallina; Bayer wrote of it, quasi Rosa redolens Lilium; Riccioli, quasi Galli rosa; and contemporaries of this last author wrote Hirezym and Hierizim. Ideler's comments on all this well show the roundabout process by which some of our star-names have originated, and are worthy ofº quotation entire:
They have, moreover, made use of the translated Greek Ὄρνις, as is shown by the Borgian Globe, on which is written Lūrnis, or Urnis (for the first letter is not connected with the second, so that we have both readings). It is most probable that from this Urnis originated the Eurisim in the foregoing rare title. Probably the translator found in the Arabic original the, to him, foreign word Urnis. He naturally surmised that it was Greek, only he did not know its proper signification. On the other hand, the plant Ἐρύσιμον (Erysimum officinale, Linn.) occurred to him, which the Romans called Ireo (see Pliny, Hist. Nat. XVIII.10XXII.25), and this recalled the richly scented Iris or Sword Lily (Iris florentina, Linn.), and so, as it seems to me, he traced the thought through a perfectly natural association of ideas to his beautiful Eurisim, quasi redolens ut lilium ab ireo. At the same time I believe I have here struck the trail of the title Albireo, which has never yet been satisfactorily explained. This is given to the star on the beak, — β, — by Bayer and in our charts. It seems to me to be nothing more than the above ab ireo, which came to be turned into an Arabic star-name by means of an interpolated l.
The early Gallina continued in use by astronomers even to the last century.
Cygnus usually is shown in full flight down the Milky Way, the Stream of Heaven, "uppoised on gleaming wings "; but old drawings have it apparently just springing from the ground.
Caesius thought that the constellation represented the Swan in the Authorized Version of Leviticus xi, 18, the Timshēmath of the Hebrews; but this is a Horned Owl in the Revision, or may have been an Ibis. Other Christians of his time saw here the Cross of CalvaryChristi Crux, as Schickard had it, Schiller's Crux cum S. Helena; these descending to our day as the Northern Cross, well known to all, and to beginners in stellar observations probably better than by the stars' true title. Lowell was familiar with it, and thus brings it into his New Year's Eve, 1844:
Orion kneeling in his starry niche,
The Lyre whose strings give music audible
To holy ears, and countless splendors more,
Crowned by the blazing Cross high-hung o'er all;
and Smith, in Come Learn of the Stars:
p195Yonder goes Cygnus, the Swan, flying southward, —
Sign of the Cross and of Christ unto me.
This Cross is formed by αγη, and β, marking the upright along the Galaxy, more than 20° in length, ζεγ, and δ being the transverse.
These last also were an Arab asterism, Al Fawāris, the Riders; α and κ sometimes being added to the group.
The Chinese story of the Herdsman, or Shepherd, generally told for our Aquila, and of his love for the skilful Spinster, our Lyra, occasionally includes stars in Cygnus.
While interesting in many respects, it is especially so in possessing an unusual number of deeply colored stars, Birmingham writing of this:
A space of the heavens including the Milky Way, between Aquila, Lyra, and Cygnus, seems so peculiarly favored by red and orange stars that it might not inaptly be called the Red Region, or the Red Region of Cygnus.
Argelander locates 146 naked-eye members of the constellation, and Heis 197, its situation in the Galaxy accounting for this density. Of these stars Espin gives a list of one hundred that are double, triple, or multiple. The Lace-work NebulaNGC 6960, also lies within its borders.
We find among classical authors ἸκτίνοςMiluusMilvus, and Mylvius, taken from the Parapegmata, and, even to modern days, supposed to be titles for our Cygnus, Aquila, or some unidentified sky figure; but Ideler showed that by these words reference probably was made to the Kite, the predaceous bird of passage annually appearing in spring, and not to any stellar object.

α, 1.4, brilliant white.

Deneb is from Al Dhanab al Dajājah, the Hen's Tail, which has become DenebadigegeDenebedigegeDeneb Adige, etc.
In the Alfonsine Tables Arided appears, and is still frequently seen for this star, as Al Ridhādh and El Rided formerly were for the constellation. Referring to this last title, Caesius termed α Os rosae, the German Rosemund, although he also designated it as Uropygium, the Pope's Nose of our Thanksgiving dinner-tables.
α also, and correctly enough, is Aridif, from Al Ridf, the Hindmost; but Bayer changed it to Arrioph, and Cary to Arion.
Bayer gave Galina as an individual title.
Mr. Royal Hill says that this and the three adjacent bright stars in the figure are known as the Triangles.
p196Deneb has no sensible proper motion, and hence had been considered as deserving the term, generally inappropriate, of a "fixed star"; but spectroscopic investigations made at Greenwich seemed to show motion at the rate of thirty-six miles a second toward the earth, and so only apparently stationary. Such motion, Newcomb says, would eventually carry it at some time, — probably between 100,000 and 300,000 years hence, — past our system at about 1/100 part of its present distance, making it the nearest and the brightest of the earth's neighbours. But Vogel's recent and more trustworthy measures at Potsdam give its rate as about five miles a second.
Elkin estimated its parallax in 1892 as 0ʺ.047, — practically insensible. Its spectrum is Sirian.
Photographs by Doctor Max Wolf, of Heidelberg, in June, 1891, show that it and γ are involved in one vastly extended nebula.
It rises in the latitude of New York City at sunset on the 12th of May, culminating on the 16th of September, and lies so far to the north that it is visible at some hour of every clear night throughout the year.

β, Double, — perhaps binary, 3.5 and 7, topaz yellow and sapphire blue.

Albireo, the now universal title, is in no way associated with Arabia, but apparently was first applied to the star from a misunderstanding as to the words ab ireo in the description of the constellation in 1515 AlmagestAlbirco in the Standard Dictionary undoubtedly is from a type error, as also may be AbbireoAlberio, and Albeiro, which occasionally are used.
The Arabians designated β as Al Minḣar al Dajājah, the Hen's Beak, where it is still located on our maps. Riccioli wrote this Menkar Eldigiagich; and also had Hierizim.
β is one of the show objects in the sky, and Miss Clerke, calling its colors golden and azure, says that it presents "perhaps the most lovely effect of colour in the heavens." Being 35ʺ apart, the components can readily be resolved by a field-glass. The system, if binary, has a very long period of revolution, as yet undetermined, the present position angle being 56°.
Close to β appeared a nova on the 20th of June, 1670, described by the Carthusian monk Anthelmus of Dijon. This disappeared after two years of varying brilliancy, but may still exist as a 10th- to 11th‑magnitude variable, discovered, in the supposed location, by Hind in 1852.
In the neck of the Swan, not far from β, is the variable χ2, ranging from 4.5 to 13.5 in 406 days. Sometimes, at its maximum, it is of only the 6th magnitude.
p197γ, 2.7, is Sadr, — incorrectly Sudr, — from Al Sadr al Dajājah, the Hen's Breast, and one of the Fawāris of the Arabs.
Reeves said that in China it was Tien Tsin, the name of a city; but this generally was given to the group of four stars, αβγ, and δ.
γ is in the midst of beautiful streams of small stars, itself being involved in a diffused nebulosity extending to α; while the space from it to βperhaps is richer than any of similar extent in the heavens. Espin asserts that around γ and the horns of Taurus seem to centre the stars showing spectra of the fourth type. Its own spectrum is Solar. According to observations at Potsdam, it is in motion toward us at the rate of about four miles a second.

ε, 2.6, yellow,

on the right wing, is Gienah, from the Arabic Al Janāḥ, the Wing.
Between αγ, and this star is the Northern Coal-sack, an almost vacant space in the Milky Way; another, still more noticeable and celebrated, coincidently being located in the Southern Cross.
6° to the northeast from ε is 61 Cygni, with a parallax of 0ʺ.5, and thus, so far as we now know, the nearest star to us in the northern heavens, with the exception of La Lande 21185 Ursae Majoris. If the distance from the earth to sun be considered as one inch, that to this star would be about seven and one half miles. It also is remarkable for its great proper motion toward the star σ, — 5ʺ.16 annually, — near to which it probably will be in 15,000 years. 4000 years ago it was near ε.
It is a double 6th‑magnitude, and may be binary, the components 20ʺ apart, with a position angle of 121° in 1890. It was the first star successfully observed for parallax, — by Bessel between the years 1837 and 1840.
ζ and ρ, with two other adjacent small stars, were the Chinese Chay Foo, a Storehouse for Carts.

π1, 4.8,

is Azelfafage, possibly a corrupted form of Adelfalferes, from Al Ṭhīlf al Faras, the Horse's Foot or Track; and, to quote Idler,
It follows either that the foot of Pegasus [now marked by π Pegasi] extended to this star, or that in this region wasº supposed to be located the feet of the Stallion which, as we shall see farther on, some Arab astronomer introduced between Pegasus and the Swan.
Or the title may be, as seems more probable, from Al ʽAzal al Dajājah, the Tail of the Hen, which it exactly marks. It is sometimes Azelfafge; but p198Bayer, with whom the word apparently first occurs, had "Azelfage id est Tarcuta."2
π1, with about twenty other stars in Cygnus, Andromeda, and Lacerta, was comprised in the early Chinese Tang Shay, the Dragon.
P, or Fl. 34, a 5th‑magnitude, located at the base of the Swan's neck, is one of few so‑called gaseous stars having bright lines in their spectra. It was discovered by Janson, as a nova of the 2d magnitude, on the 18th of August, 1600; was numbered 27 in Tycho's catalogue, with the designation of nova anni 1600 in pectore Cygni; and Kepler thought it worthy of a monograph in 1606. Christian Huygens, the Dutch astronomer of the 17th century, called it the Revenante of the Swan, from its extraordinary light changes; but these now seem to have ceased.

ω3, Double, 5½ and 10, pale red,

is Ruchba from Al Rukbah al Dajājah, the Hen's Knee; but the three stars ω now mark the tertiaries of the left wing.
The components of ω3 are 56ʺ.3 apart, at a position angle of 86°.3; and other minute stars are in the same field.

The Author's Notes:

1 While Cygnus was thus prominent in myth and the sky, the swan was especially so in ancient ornithology, and the subject of many fables, where its "hostility" to other birds and to beasts was made much of; but in these Thompson sees astronomical symbolism, as already has been alluded to under Aquila.

2 What is this last? It seems to have escaped comment by all of the authorities.