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Just below the Scorpion is a scattered group of stars of medium brightness forming Sagittarius, the Archer who was pictured by the ancients as shooting an arrow at the Scorpion.
The Milky Way is particularly bright in this section. It is thought that this is the direction in which the centre of the Galaxy lies, and that this represents the greatest "thickness" or concentration of stars as seen from the earth.
Returning to the Cross and following the line of its axis upward, i.e., away from Achernar, beyond the zenith, one sees the distorted square of Corvus , the Crow, and close by, a very bright star which is Spica or Alpha of the Virgin. This constellation, together with Scorpio and Sagittarius, are southern parts of the Zodiac—the belt of the sky along which the Sun, Moon and planets appear to travel. The light of the sun, of course, blots out the surrounding stars except during a total eclipse, but the Moon and the planets can be seen to pass close to, and sometimes actually over, some of the stars in these constellations.
The hour of 9 p.m. was suggested as the standard time of observation be- cause, Summer or Winter, it is then dark enough to see the stars; but, as all the constellations make one circuit in a little under 24 hours, their position some time before or after this hour can be readily appreciated. For ex am ple, in May, the whole star pattern of 9 p.m. will have turned a quarter circle in the 6 hours following 9 p.m. , so that at 3 a.m. the Cross lies on its side toward the west, and therefore points to the hour of 6 on our clock. This corresponds with the 9 p.m. star position for August, for the gain in three months is six hours.
Thus, at any time of the night and at any period of the year, the star position is quickly determined, and the various constellations easily located.
Toward the end of the year when, at 9 p.m. , the positions of our "key" stars are reversed, or rather, have rotated through half a circle, the Cross is near the horizon, Achernar is high overhead, Alpha Pavonis marks the hour of 4, while Canopus is toward the east at the eighteenth hour on the dial.
At this time, the Milky Way extends almost horizontally around the greater part of the horizon.
Due east, Orion is rising, and from there a long meandering line of faint stars shows the course of the River Eridanus right up to Achernar, its "mouth."
Orion is easily recognised, as three fainter spots of the "sword" projecting from the "belt" form the handle of a shapely saucepan of which the three brighter, evenly-spaced stars of the belt form the base.
A little later, when this constellation is higher in the sky, an interesting contrast of star colors can be observed in Rigel and Betelgeuse, the two brightest stars in Orion. These are above and below the "belt," and there is no mistaking one for the other as Rigel is in-tensely blue-white, while Betelgeuse is a red giant like Antares.
Just to the right of Achernar is Grus, the Crane, flying upside down now, and above him, almost at the zenith, is a very bright star which is Fomalhaut, Alpha of the constellation of the Southern Fish. Grus is composed of three conspicuous stars in triangular formation, representing the wings, with four fainter doubles and triples trailing behind like a crane's long legs.
Besides all these stars already discussed, there are, of course, very many more that could not possibly be covered in this short account. For the am ateur astronomer there are limitless fields that can carry him far beyond the bounds set by these pages, and few hobbies can be more interesting. And for the scientist himself, also, there is yet a great deal to be learned. The Heavens still hold many vital secrets , and studying them and discovering them must remain one of the most fascinating of occupations.
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