West of Corona the most conspicuous object is Arcturus in Boötes. This entire constellation is now well placed for observation. But first a few words about Arcturus, a star of which one can never tire, so steeped is it in the poetry and history of the most interesting nations of the past. Like Alpha Centauri, Arcturus was used as a “temple star” in both Egypt and Greece, and it was of much importance as a prognosticator of the seasons. When a conspicuous star was seen rising just ahead of the sun, it was said to rise heliacally, and it served as a sentinel to announce the oncoming day. To the priests this was important, because it warned them of the moment when it was necessary to begin their preparations for the sunrise ceremonies in the temples. To the husbandman such a herald seemed specially connected with the particular season in which it appeared. In this way Arcturus came to give its name to the ancient Greek autumn. In Sophocles’ Œdipus the King there is a passage which affords striking evidence of the popular knowledge of Arcturus in this connection. When the herdsman from Mount Cithæron is brought to prove that he had nurtured Œdipus as a child, one of his former comrades, to recall the old man’s recollections, reminds him that they had kept their flocks together “three whole half-years from Spring to Arcturus” (meaning from Spring to Autumn, since Arcturus then rose heliacally at the beginning of September). Whatever might be the local names for Autumn, over all the Greek world it was popularly known as the “time of Arcturus.”
Although the Revised Version has struck out Arcturus and substituted “the Bear” in that famous passage in which the Almighty answers Job “out of the whirlwind,” yet for lovers of the Bible this will always be “Job’s Star,” always surrounded to the imagination with the momentous circumstances suggested by that tremendous and unanswerable demand:
“Canst thou call forth Arcturus and his sons?”
No scientific fact known about it—not its gigantic size, not its inexplicable flight through space—can be so imposing as the impressions conveyed in its choice by Jehovah to illustrate His illimitable power. One likes to think that the Hebrew poet really did mean to write “Arcturus,” for there is something sublime in the idea of representing the Great Maker of All as calling one of His stars by name.
Arcturus is sometimes referred to under the name of Arctophilax, the “Bear-driver,” a name properly belonging to the constellation Boötes. In modern astronomical history it will always be memorable for the passage over it of the celebrated Comet of 1858, Donati’s Comet. At one time the star was almost involved in the head of the great comet, and yet it shone through the obstructing vapors with virtually undiminished lustre. It was a spectacle, said Professor Nichol, the like of which no one might see again though he should spend on earth fifty lives. At the beginning the comet was a little plume of fire, “shaped like a bird of paradise,” but it soon brightened into a stupendous scimetar, brandished in the sunset, and when it swept over Arcturus the whole astronomical world was watching to see what would happen to the star.
Among the other stars of Boötes, Epsilon (ε) is specially worthy of notice, being a remarkable binary of finely contrasted colors, orange and sea-green. The distance is 2″.25, and the period of revolution long but undetermined. Struve called this star “Pulcherrima,” on account of its exceeding beauty.
Although Arcturus by its splendor belittles the rest of the constellation, yet it requires no difficult exercise of the imagination to see a giant form there, towering behind the Bear, and urging on his dogs in the chase. The dogs are represented by Canes Venatici, of the beauty of whose chief star, Cor Caroli, I have spoken in the preceding chapter. In the upper part of Canes Venatici, about 3° southwest of Benetnasch, is the celebrated “Whirlpool Nebula” of Lord Rosse, which modern photographs show in a form so suggestive of tremendous disruptive forces that cosmogonists are at a loss to explain it.
We now drop down to Libra, the “Balance,” which lies just west of Scorpio and east of Virgo. There is evidence that this constellation originally represented the outstretched claws of the Scorpion. Yet as an independent constellation it is very ancient. It has only two stars of any considerable magnitude, Alpha (α) and Beta (β). The former must have faded, for it is now the fainter. It lies almost on the ecliptic. These stars are interesting on account of their curious names, which themselves tend to prove that Libra once formed a part of Scorpio. Alpha is Zubenelgenubi, the “Southern Claw,” and Beta Zubeneschemali, the “Northern Claw.” These titles, as Allen shows, have been derived through the Arabic from the Greek names current in the time of Ptolemy. The first is yellowish-white, and the second pale green. Any good eye detects the difference of color at a glance, although the stars are about ten degrees apart. Zubenelgenubi is widely double, separable with an opera-glass.
Along the western horizon we recognize our old friends Virgo, Corvus, and Leo, while high in the northwest is Ursa Major, head downward, and directly in the north Ursa Minor, standing on the end of his tail, poised like an acrobat on Polaris. The head of Draco shows finely east of the meridian, and low down in the northeast is the “Laconian Key” of Cassiopeia. But that is for another evening.