mercredi 1 octobre 2008

Triangulum 5

Five splendid Stars in its unequal Frame
Deltoton bears, and from the shape a Name;
But those that grace the sides dim Light display
And yield unto the Basis brighter Ray.

Triangulum, the German Dreieck, the French and English Triangle, and the Italian Triangolo, appeared as Triangulus in the Rudolphine Tables, always qualified p415as major till the Lesser Triangle was discarded. It lies just south from γ Andromedae on the edge of the Milky Way, and although small and faint notwithstanding our poet's description, is one of the old constellations evidently more noticed by the ancients than by us. They drew it as equilateral, but now it is a scalene figure, β, δ, γ at the base and α at the vertex.
Hood strangely said that it was placed in the heavens only that the head of Aries might be better known, which recalls the blunder of Aratos as to the faintness of Aries' stars.
It was Δελτωτόν with the earlier Greeks, from their similarly shaped letter Δ, to which Ovid in his Nux likened it; as did Aratos in his lines that Brown renders, more literally than rhythmically:
Below Andromeda, in three sides measured
Like-to‑a‑Delta; equal two of them
As it has, less the third, yet good to find
The sign, than many better stored with stars.
Transcribed by Cicero and Hyginus as Deltoton, it became Deltotum with the Romans, as well as with astronomers to the 17th century. Naturally it also was Delta, and so, associated with Egypt and the Nile, became Aegyptus, Nilus, Nili Domum, the Home of the Nile, which originally was Nili Donum, the Gift of the Nile, from Herodotus' ποταμοῦ δῶρον, "the river's gift."
Τρίγωνον, used by Hipparchos and Ptolemy, became Trigonum with Vitruvius, and Trigonus with Manilius, translated Trigon by Creech. Tricuspis, Three-pointed, and Triquetrum, the Trinal Aspect of astrology, are found for it; while Bayer had Triplicitas and Orbis terrarum tripertitus as representing the three parts of the earth, Europe, Asia, and Africa; and Triangulus Septentrionalis, to distinguish it from his own Southern Triangle.
Pious people of his day said that it showed the Trinity, its shape resembling the Greek initial letter of Δῖος; while others of the same sort likened it to the Mitre of Saint Peter.
Its titles Sicilia, Trinacria, and Triquetra are those of the ancients for the similarly shaped island of Sicily, — that Ceres had begged of Jove might be reproduced in the sky, — triangular from its three promontories, Lilybaeum, Pelorus, and Pachynus, and at times identified with the mythical Thrinakia of the Odyssey, the pasture-ground of the Oxen of the Sun, that Gower called Mela's Holy Ox-land. In modern days it has been noted as the site of the famous Palermo Observatory.
It was here that was discovered by Piazzi, on the first New Year Day of the present century, the first minor planet, which he named Ceres p416Ferdinandea in joint honor of the patron goddess of the island and of his king, the Bourbon Ferdinand of Naples; but the adjective has been dropped by astronomers as not conforming to their rule of mythological nomenclature for the planets, — a rule, however, much deviated from in recent times in the naming of these little bodies. Perhaps the astronomers have exhausted their classical dictionaries! It was found This, like many other important discoveries, was by a happy accident, — Piazzi, very differently, being in search of an extra star, the eighty-seventh of Mayer's list, wrongly laid down in Wollaston's catalogue.
Recent measurements by Barnard show that Ceres is only a little less than 500 miles in diameter, and thus the first in size of the minor planets as in order of discovery, as an 8th‑magnitude star — Flammarion says as a comet — between Aries and Taurus, coincidentally not far from our Triangulum, the ancient Sicilia; but it was little imagined at the time that 433 similar bodies would be found in the next ninety-seven years, more than 150 of them since 1892, and all but seven of these last by photography, The first of such discoveries by the camera was by Wolf on the 20th of December, 1891, of Brucia, No. 333; the first applications of the new art to the heavens having been made with the daguerreotype process by Doctor John W. Draper, of New York City, on the moon in 1840; again, by the professional Whipple of Boston, under Bond's direction, at the Harvard Observatory, on the star Wega in 1850; and at the same place on Mizar and Alcor in 1857. The first photograph of a star's spectrum was in 1872; of a nebula, in 1880; of a comet (near the sun during the latter's total eclipse), in 1882; and of a meteor, in 1891, then an unknown art.
The Arabians translated our title as Al Muthallath, variously seen in Western usage as Almutallath, Almutaleh, Almutlato, Mutlat, Mutlaton, Mutlathum, Mutlathun, and Mutlatun, with probably still other similarly degenerated forms of the original.
The Jews are said to have known it as Shālīsh, from the name of an instrument of music of triangular shape, or with three cords, mentioned in the 1st Book of Samuel, xviii.6. This same figure, for the three bright stars of Aries, has already been noticed at γ of that constellation.
Heis enumerates here 30 naked-eye components, but Argelander only 15.
The Chinese asterism Tsien Ta Tseang, Heaven's Great General, included this with λ of Andromeda and the stars of the Smaller Triangle.

Aucun commentaire: