The renown of Sirius is as ancient as the human race. There has never been a time or a people in which or by whom it was not worshipped, reverenced, and admired. To the builders of the Egyptian temples and pyramids it was an object as familiar as the sun itself. Its name is usually regarded as being derived from the Greek Σείριος, the “Bright or Shining One,” but it is also thought that it may be connected with Osiris. The familiar title of the “Dog Star” comes from its association with the dies caniculariæ of the Romans.
“As the movable Egyptian year,” says George Cornewell Lewis, “was held to have originally begun at the heliacal rising of the Dog Star, which was contemporary with the ordinary commencement of the inundation of the Nile, this period was, by late writers, entitled the Canicular, or Sothiac, period, Sothis being the Egyptian name for the Dog Star.”
Norman Lockyer identifies Sirius with the goddess Isis, or Hathor, who was personified by that star, and the temple of Isis at Dendera was, he avers, built to watch it. “It has been pointed out, times without number,” he adds, “that the inscriptions indicate that by far the most important astronomical event in Egyptian history was the rising of the star Sirius at this precise time.”
Sirius has sometimes been identified with the “Mazzaroth” of the Book of Job.
The great star is worthy of all its fame, not only by its magnificent beauty, but by the revelations which modern science has afforded us concerning it. While not comparable in actual luminosity with Rigel, Canopus, or even Arcturus, it immensely outshines the best of them to our eyes because of its relative nearness. Its distance is only about 50,000,000,000,000 miles (parallax 0″.37), so that it is really one of the nearest stars in the sky. Light requires about nine years to come to us from Sirius. Outshining the sun at least thirty times, it is so bright, even at that distance, that a special rank has been given to it in stellar photometry. Formerly all very bright stars were ranked as of the first magnitude, but greater exactness is now employed, the naked-eye stars being divided among eight magnitudes, running from 6 up to -1. Thus the faintest star visible to the naked eye is of magnitude 6; a star 2.51 times brighter is of magnitude 5; a star 2.51 times brighter than that is of magnitude 4, and so on up to magnitude 1. A star 2.51 times brighter than magnitude 1 is of magnitude 0; and one 2.51 times brighter than the 0 magnitude is of magnitude -1, a degree of brilliance which is attained by Sirius alone. In fact, Sirius exceeds magnitude -1, its real rank being -1.6. On the same scale the magnitude of the sun would be -26.3. The standard first magnitude s usually taken as being represented by the star Altair, although that star is not exactly of that magnitude. As a ready rule it may be said that each magnitude is two and a half times brighter than the next below it, and a difference of six magnitudes corresponds to an increase of one hundred times in brilliance. Sirius is about ten times as bright as Altair. While, if seen from the same distance, Sirius would appear at least thirty times as bright as the sun, at our actual distance from both the light received from the sun is to that received from Sirius in the ratio of about 7,000,000,000 to 1. While by no means the largest sun in the universe, Sirius is the largest sun in our part of space, and some indications have been detected that it may, to a certain extent, control the motion of the solar system. In other words, our sun and some of the nearer stars appear to form a group, or family, of which Sirius is probably the chief.
Sirius is an intensely white star, but its whiteness is shot with a tint of blue or green. It has not the purity of light of Spica. Owing also to its great brilliance, it twinkles incessantly, darting, in an unsteady atmosphere, rays of all the colors of the rainbow. The spectroscope shows that it is a sun at an earlier stage of development than ours. It is also a binary. A very massive companion, singularly faint for its size, revolves round it in a period of about fifty-three years. At present the distance between these stars is more than 6″. The small star is more than half as massive as Sirius, but ten thousand times less brilliant—one would say a dying sun linked by gravitation with another in the heyday of its life and splendor.
The constellation Canis Major, of which Sirius is the leader, is very striking in outline when well above the horizon. Some six degrees west of Sirius is seen the second star of the constellation, Beta (β), or Murzim (Arabic Al Murzim, the “Announcer”), a name which Ideler says originated in the fact that this star rises ahead of Sirius, and thus appears to announce its coming. The remainder of the constellation should be viewed an hour or two later than that for which [Chart IV] is drawn, or a month later in the season, when it is farther from the horizon. It represents the hind-quarters of the imaginary dog. The star Epsilon (ε), or Adhara, perhaps the brightest in the group, is a double; colors orange and violet; distance 7″.5. The smaller star is of only the ninth magnitude. Delta (δ) is called Wezen, the “Weight,” because “the star seems to rise with difficulty from the horizon,” an excellent instance of the fanciful titles which the Arabs and others often gave to stars. Zeta (ζ) is Furud, and Eta (η) Aludra. The meaning of these names is uncertain. Allen says that the Arabs called Epsilon, Delta, Eta, and Omicron (ο) “The Virgins.” But they had other names for them suggested by fancied resemblances as they rose sparkling from the desert.
From Canis Major the eye rises to Orion, the most glorious of all constellations:
“Whoso kens not him in cloudless night
Gleaming aloft, shall cast his eyes in vain
To find a brighter sign in all the heaven.”
Brown, in his Primitive Constellations, undertakes to derive the name from the Akkadian Uru-anna, the “Light of Heaven.” Whatever its origin, it is certainly very ancient. For some thousands of years it has been associated with a traditional giant who looms in the background of Greek mythology. In the classical atlases of the heavens Orion is represented as standing in an attitude of defiance, facing westward, brandishing a huge club above his head, and lifting his left arm, covered with a lion’s hide, to meet the charge of Taurus, the “Bull.” And under some such guise all mankind has seen him for untold ages—always a gigantic figure, always heroic in character, always defying or pursuing—the symbol of strength, courage, conquest, and victory. The same idea underlies every representation of this constellation; whether it be the mythical “Giant” of the East, or “Nimrod” or “Joshua” or the “Armed King” or the “Warrior” or the “Hunter,” it is invariably the figure of a doer of great deeds which is presented to the imagination. And it must be said that the aspect of the constellation is in accord with such thoughts. No one can look at it without a stirring of the blood. It has something of the effect of a great battle-piece, and it is not surprising that they once endeavored in France to connect it with the name of Napoleon. Although its two chief stars are separated some eighteen degrees, and the central “Belt” forms a striking figure by itself, yet there is an unmistakable unity about the constellation, and one would hardly think of dividing it into separate groups. Singularly enough, this sense of oneness is borne out by the photographic discovery that a vast swirl of nebulous matter surrounds the entire constellation, and by the spectroscopic proof that nearly all of its stars belong to one type, which has become known as the “Orion type.”