Astronomy for Amateurs

the third (Fig. 12). The most brilliant are Betelgeuse (α) and Rigel (β): the former marking the right shoulder of the Colossus as it faces us; the second the left foot. The star on the left shoulder is γ or Bellatrix, of second magnitude; that of the right foot, χ, is almost of the third. Three stars of second magnitude placed obliquely at equal distances from each other, the first or highest of which marks the position of the equatorial line, indicate the Belt or Girdle. These stars, known as the Three Kings, and by country people as the Rake, assist greatly in the recognition of this fine constellation. A little below the second star of the Belt, a large white patch, like a band of fog, the apparent dimensions of which are equal to that of the lunar disk, is visible to the unaided eye: this is the Nebula of Orion, one of the most magnificent in the entire Heavens. It was discovered in 1656 by Huyghens, who counted twelve stars in the pale cloud. Since that date it has been constantly studied and photographed by its many admirers, while the giant eye of the telescope discovers in it to-day an innumerable multitude of little stars which reveal the existence of an entire universe in this region. Orion is not merely the most imposing of the celestial figures; it is also the richest in sidereal wonders. Among[Pg 50] these, it exhibits the most complex of all the multiple systems known to us: that of the star θ situated in the celebrated nebula just mentioned. This marvelous star, viewed through a powerful telescope, breaks up into six suns, forming a most remarkable stellar group. This region is altogether one of the most brilliant in the entire firmament. We must no longer postpone our homage to the brightest star in the sky, the magnificent Sirius, which shines on the left below Orion: it returns every year toward the end of November. This marvelous star, of dazzling brilliancy, is the first, α, in the constellation of the Great Dog, which forms a quadrilateral, the base of which is adjacent to a triangle erected from the horizon. When astronomers first endeavored to determine the distance of the stars, Sirius, which attracted all eyes to its burning fires, was the particular object of attention. After long observation, they succeeded in determining its distance as 92 trillion kilometers (57 trillion miles). Light, that radiates through space at a velocity of 300,000 kilometers (186,000 miles) per second, takes no less than ten years to reach us from this sun, which, nevertheless, is one of our neighbors. The Little Dog, in which Procyon (α, of first magnitude) shines out, is above its big brother. With the exception of α, it has no bright stars. [Pg 51] Fig. 13.—Winter Constellations. Lastly, toward the southern horizon, we must notice the Hydra, Eridanus, the Whale, the Southern Fish, the Ship, and the Centaur. This last constellation, while invisible to our latitudes, contains the star that is[Pg 52] nearest to the Earth, α, of first magnitude, the distance of which is 40 trillion kilometers (25 trillion miles). Fig. 14.—Spring Constellations. The feet of the Centaur touch the Southern Cross, which is always invisible to us, and a little farther[Pg 53] down the Southern Pole reigns over the icy desert of the antarctic regions. Fig. 15.—Summer Constellations. [Pg 54] Fig. 16.—Autumn Constellations. In order to complete the preceding descriptions, we subjoin four charts representing the aspect of the starry heavens during the evenings of winter, spring, summer, and autumn. To make use of these, we must suppose them to be placed above our heads, the center marking the zenith, and the sky descending all round to the horizon.[Pg 55] The horizon, therefore, bounds these panoramas. Turning the chart in any direction, and looking at it from north, south, east, or west, we find all the principal stars. The first map (Fig. 13) represents the sky in winter (January) at 8 P.M.; the second, in spring (April) at 9 P.M.; the third, in summer (July) at the same hour; the fourth, the sky in autumn (October) at the same time. And so, at little cost, we have made one of the grandest and most beautiful journeys conceivable. We now have a new country, or, better, have learned to see and know our own country, for since the Earth is a planet we must all be citizens of the Heavens before we can belong to such or such a nation of our lilliputian world. We must now study this sublime spectacle of the Heavens in detail. [Pg 56]