Page:Popular Science Monthly Volume 47.djvu/216

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THE POPULAR SCIENCE MONTHLY.

resolve into separate stars to its very center—a scene of marvelous beauty and impressiveness. But smaller instruments reveal only the in-running star streams and the sprinkling of stellar points over the main aggregation, which cause it to sparkle like a cloud of diamond dust transfused with sunbeams. The appearance of flocking together that those uncountable thousands of stars present calls up at once a picture of our lone sun separated from its nearest stellar neighbor by a distance probably a hundred times as great as the entire diameter of the spherical space within which that multitude is congregated. It is true that unless we assume what would seem an unreasonable remoteness for the Hercules cluster, its component stars must be much smaller bodies than the sun; yet even that fact does not diminish the wonder of their swarming. Here the imagination must bear science on its wings, else science can make no progress whatever.

It is an easy step from Hercules to Draco. In the conspicuous diamond-shaped figure that serves as a guideboard to the head of the latter, the southernmost star belongs not to Draco but to Hercules. The brightest star in this figure is γ, of magnitude two and a half, with an eleventh-magnitude companion, distant 125″, p. 116°. Two stars of magnitude five compose ν, their distance apart being 62″, p. 312°. A more interesting double is μ, magnitudes five and five, distance 2·4″, p. 158°. Both stars are white, and they present a pretty appearance when the air is steady. They form a binary system of unknown period. Σ 2078 (also called 17 Draconis) is a triple, magnitudes six, six and a half, and six, distances 3·8″, p. 116°, and 90″, p. 195°. Σ 1984 is an easy double, magnitudes six and a half and eight and a half, distance 6·4″, p. 270°. The star η is a very difficult double for even our largest aperture, on account of the faintness of one of its components. The magnitudes are two and a half and ten, distance 4·7″, p. 140°. Its near neighbor, Σ 2054, may be a binary. Its magnitudes are six and seven, distance 1″, p. 0°. In Σ 2323 we have another triple, magnitudes five, eight and a half, and seven, distances 3⋅6″, p. 360°, and 90″, p. 22°, colors white, blue, and reddish. A fine double is ε, magnitudes five and eight, distance 3″, p. 5°.

The nebula No. 4373 is of a planetary character, and interesting as occupying the pole of the ecliptic. A few years ago Dr. Holden, with the Lick telescope, discovered that it is unique in its form. It consists of a double spiral, drawn out nearly in the line of sight, like the thread of a screw whose axis lies approximately endwise with respect to the observer. There is a central star, and another fainter star is involved in the outer spiral. The form of this object suggests strange ideas as to its origin. But the details mentioned are far beyond the reach of our instruments.