mercredi 1 octobre 2008

Canis Major 8

Fierce on her front the blasting Dog-star glowed.

Samuel Taylor Coleridge's On the French Revolution.

One blazes through the brief bright summer's length,
Lavishing life-heat from a flaming car.

Christina G. Rossetti's's Later Life.
Canis Major, the Greater Dog, of the southern heavens, and thus Canis Australior, lies immediately to the southeast of Orion, cut through its centre by the Tropic of Capricorn, and with its eastern edge on the Milky Way.
It is Cane Maggiore in Italy; Cães in Portugal; Grand Chien in France; and Grosse Hund in Germany.
In early classical days it was simple Canis, representing Laelaps, the hound of Actaeon, or that of Diana's nymph Procris, or the one given to Cephalus by Aurora and famed for the speed that so gratified Jove as to cause its transfer to the sky. But from the earliest times it also has been the Dog of Orion to which Aratos alluded in the Prognostica, and thus wrote of in the Phainomena in connection with the Hare:
The constant Scorcher comes as in pursuit,
. . . and rises with it and its setting spies.
Homer made much of it as Κύων, but his Dog doubtless was limited to the star Sirius, as among the ancients generally till, at some unknown date, the constellation was formed as we have it, — indeed till long afterwards, for we find many allusions to the Dog in which we are uncertain whether the constellation or its lucida is referred to. Hesiod and Aratos gave this title, both also saying Σείριος, and the latter μέγας; but by this adjective he designed only to characterize the brilliancy of the star, and not to distinguish it from the Lesser Dog. The Greeks did not know the two Dogs thus, nor did the comparison appear till the days of the Roman Vitruvius. p118Ptolemy and his countrymen knew it by Homer's title, and often as Αστροκύων, although it seems singular that the former never used the word Σείριος.
The Latins adopted their Canis from the Greeks, and it has since always borne this name, sometimes even Canicula in the diminutive (with the adjectival candens, shining), Erigonaeus, and Icarius; the last two being from the fable of the dog Maera, — which itself means Shining, — transported here; her mistress Erigone having been transformed into Virgo, and her master Icarius into Boötes. Ovid alluded to this in his Icarii stella proterva canis; and Statius mentioned the Icarium astrum, although Hyginus had ascribed this to the Lesser Dog.
Sirion and Syrius occasionally appeared with the best Latin authors; and the Alfonsine Tables of 1521 had Canis Syrius.
Vergil brought it into the 1st Georgic as a calendar sign,—
adverso cedens Canis occidit astro,—
instructing the farmer to sow his beans, lucerne, and millet at its heliacal setting on the 1st of May; the adverso here generally being referred to the well-known reversed position of the figure of Taurus, but may have been intended to indicate the hostility of the Bull to the Giant's Dog that was attacking him.
Custos Europae is in allusion to the story of the Bull who, notwithstanding the Dog's watchfulness, carried off that maiden; and Janitor Lethaeus, the Keeper of Hell, makes him a southern Cerberus, the watch-dog of the lower heavens, which in early mythology were regarded as the abode of demons: a title more appropriate here than for the so-named modern group in the northern, or upper, sky.
Bayer erroneously quoted as proper names Dexter, Magnus, and Secundus, while others had Alter and Sequens; but these originally were designed only to indicate the Dog's position, size, and order of rising with regard to his lesser companion.
The aestifer of Cicero and Vergil referred to its bright Sirius as the cause of the summer's heat, which also induced Horace's invidum agricolis; and Bayer's Ὑδροφοβία was from the absurd notion, prevalent then as now, of the occurrence of canine madness solely during the heat from the Dog-star: an idea first seen with Asclepiades of the 3rd century before Christ. Or it may have come from being confounded by Bayer, none too careful a compiler, with the Ὑδραγωγόν, which Plutarch applied to Sirius in his De Iside, What Allen actually has is "De Isidoro"; but there is no such work by Plutarch. The reference is to the opening sentence of chapter 38 (366A) of De Iside et Osiride, Τῶν τ᾽ ἄστρων τὸν σείριον Ἴσιδος νομίζουσιν, ὑδραγωγὸν ὄντα. The lesson a student can learn from this, of course, is to make quite sure you know what you're abbreviating! "Isid." usually stands for Isidore, a different writer altogether; and "de Isid." for the work by Plutarch. signifying the Water-bringer, i.e. the cause of the Nile flood.
Aratos termed the constellation ποικίλος, as of varying brightness in its different parts; or mottled — the Dog, lying in as well as out of the Milky Way, being thus diversified in light.
In early Arabia, as indeed everywhere, it took titles from its lucida, although strangely corrupted from the original Al Shīʽrā al ‘Abur al Yamaniyyah, the Brightly Shining Star of Passage of Yemen, in the direction of which province it set. Among these we see, in the Latin Almagest of 1515, "canis: et est asehere, alahabor aliemenia"; in the edition of 1551, Elscheere; in Bayer's Uranometria, Elseiri (which Grotius derived from σείριος), Elsere, Sceara, Scera, Scheereliemini; in Chilmead's Treatise, Alsahare aliemalija; and Elchabar, which La Lande, in his I'Astronomie, not unreasonably derived from Al Kabir, the Great.
The Arabian astronomers called it Al Kalb al Akbar, the Greater Dog, so following the Latins, Chilmead writing it Alcheleb Alachbar; and Al Bīrūnī quoted their Al Kalb al Jabbār, the Dog of the Giant, directly from the Greek conception of the figure. Similarly it was the Persians' Kelbo Gavoro.
It was, of course, important in Euphratean astronomy, and is shown on remains from the temples and mounds, variously pictured, but often just as Aratos described it and as drawn on maps of the present day, — standing on the hind feet, watching or springing after the Hare. Professor Young describes the figure as one "who sits up watching his master Orion, but with an eye out for Lepus."
Bayer and Flamsteed alone among its illustrators showed it as a typical bulldog.
A Dog, presumably this with another adjacent, is represented on an ivory disc found by Schliemann on his supposed site of Troy; and an Etruscan mirror of unknown age bears it with Orion, Lepus, the crescent moon, and correctly located neighboring stars, while both of the Dogs, the Dragon, Fishes, Swan, Perseus, the Twins, Orion, and the Hare are described as on the Shield of Hercules in the old poem of that title generally attributed to Hesiod. The Hindus knew it as Mrigavyādha, the Deer-slayer, and as Lubdhaka, the Hunter, who shot the arrow, our Belt of Orion, into the infamous Praja-pati, where it even now is seen sticking in his body; and, much earlier still, with their prehistoric predecessors it was Saramā, one of the Twin Watch-dogs of the Milky Way.
Among northern nations it was Greip, the dog in the myth of Sigurd.
All of these doubtless referred solely to Sirius.
Novidius, who imagined biblical significance in every starry group, said that this was the Dog of Tobias in the Book of Tobit, v.16, which Moxon p120confirmed "because he hath a tayle," and for that reason only; but Julius Schiller, another of the same school, saw here the royal Saint David.
Gould catalogued 178 stars down to the 7th magnitude.

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