XII NOVEMBER
Directly south of Cassiopeia and Cepheus, the circumpolar constellations with which we became acquainted last month, and almost overhead in our latitudes in the early evening hours of November, lie Pegasus, The Winged Horse, and Andromeda, The Woman Chained.
According to the legend, Cepheus was king of Ethiopia, and Cassiopeia was the beautiful, but vain, queen who dared to compare herself in beauty with the sea-nymphs. This so enraged the nymphs that, as a punishment for her presumption, they decided to send a terrible sea-monster to ravage the coast of the kingdom. The king and queen, upon consulting the oracle, found that the only way to avert this calamity would be to chain their daughter Andromeda to the rocks and permit the monster to devour her.
November—Andromeda and Pegasus
As the story goes, the valiant hero, Perseus, chanced to be riding through the air on his winged horse and saw, far beneath him the beautiful maiden chained to the rocks and the frightful monster approaching to devour her. He immediately went to the rescue, and, after a terrible struggle with the monster, succeeded in overpowering him and thus saved the maiden from a dreadful fate. Perseus and the fair Andromeda were married shortly afterward, and at the end of a happy life the pair were transferred to the heavens. Cassiopeia, the vain queen, was ordered to be bound to a chair and, with the king Cepheus at her side, to be swung continually around the north pole of the heavens that she might be taught a lesson in humility.
The constellation Cetus, representing the sea-monster, will be found to the southeast and south of Pisces, The Fishes, which lie south of Andromeda and Pegasus.
The Great Square in Pegasus is the most conspicuous configuration of stars to be seen in the heavens in autumn evenings. The star that marks the northeastern corner of The Great Square belongs to the constellation of Andromeda and marks the head of the maiden, who is resting upon the shoulders of Pegasus, The Winged Horse. The three bright stars nearly in a straight line outline the maiden's body, Alpha, or Alpheratz, as it is called, being the star in the head, Beta or Mirach in the waist, and Gamma or Almach in the left foot. The last-named star, which is farthest to the northeast in the diagram, was, in the opinion of the noted astronomer Herschel, the finest double star in the heavens. The two stars into which the telescope splits it are of the beautifully contrasted shades of orange and sea green.
A second most interesting object in Andromeda and one of the finest in the entire heavens is The Great Andromeda Nebula, which is faintly visible without the aid of a telescope as a hazy patch of light. It is believed that in reality this nebula is a great universe composed of many thousands of stars so distant that no telescope can show the individual members and that the light from it takes many thousands of years to span the abyss that separates it from the solar system. Some magnificent photographs of The Great Andromeda Nebula have been taken with powerful telescopes. It is through the use of photography that the nebulæ can best be studied, for a photographic plate after long exposure, reveals a wonderful detail in the structure of these objects that the human eye fails to see. On a clear, dark evening one may find The Great Andromeda Nebula by the aid of two faint stars with which it makes a small triangle, as shown in the chart. This nebula is the only one of the spiral nebula that can be seen in these latitudes without the aid of a telescope, though there are several spiral nebulæ in the southern heavens that can be thus seen.
Lying to the northwest of The Great Square in Pegasus are a number of faint stars that outline the shoulders and head of the winged steed, while the stars to the southwest of the square outline his forelegs. The creature is represented without hind quarters in all star atlases. The space within The Great Square contains no bright stars, and as a result, the outline of the square stands out with great distinctness. There are, in fact, no stars of the first magnitude in either Pegasus or Andromeda, though there are a number of the second and third magnitude which very clearly show the distinctive forms of these two star-groups.
Pisces, The Fishes, the constellation just south of Andromeda and Pegasus, is the first of the twelve zodiacal constellations. It consists of the southern fish, lying in an east-to-west direction, and the northern fish, lying nearly north and south, the two touching at the southeastern extremity of the constellation.
November—Pisces
There is in Pisces not a single bright star, and its only point of interest is to be found in the fact that it contains the point, marked by the cross and letter V in the diagram, that is known variously as "the vernal equinox," "the equinoctial point" and "The First Point in Aries." This is a very important point of reference in the heavens, just as the meridian of Greenwich is for the earth, and it marks the point where the sun crosses the equator going north in the spring. Owing to the Precession of the Equinoxes, as it is called, this point is gradually shifting its position westward through the zodiacal constellations at a rate that will carry it completely around the heavens through the twelve zodiacal groups in a period of 25,800 years.
Since the beginning of the Christian era, this point has backed from the constellation of Aries, which lies just east of Pisces, into Pisces, though it still retains its name of "The First Point in Aries."