solar star

The name given to those stars which from the spectrum analysis of their light are supposed to be in the same state of heat, . as our central sun is at the present time. "Arcturus belongs to the cla of solar stars-stars which are thought on the testimony of their spectra to be in about the same condition physically as the sun. Vega belongs to the cla of which Sirius is the most illustrious representative-stars which are supposed to be in an earlier stage of world-life and to be intensely hot as well as intensely brilliant."- Chicago Tribune , Aug. 5, 1894. solar-system, s . Astron.: The sun and the various bodies which revolve around him, deriving from him their light and heat. The enumeration of these bodies, deemed by the ancients complete, was: The Earth (in the center), then the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn, seven in all. [WEEK.] Now planets, primary and secondary, are regarded as only one, though certainly a very important, part of the solar system. Of the major planets, called simply the planets, eight are recognized Mercury. Venus, the Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Of the secondary planets satellites, including the moon, twenty-one. Among other bodies revolving around the sun in more or le eccentric orbits are many comets, and a number of meteoric rings, some of which have been found to have a close relation to certain comets. or The orderly movements of the several bodies in the solar system is effected mainly by gravitation. Loosely stated, the planets revolve around the Sun. What really takes place is that they revolve around the center of gravity common to him and them, but their his ma so much outweighs the aggregate ma es that the point around which the revolution takes place, though not the sun's center, is still within his ma . Their revolution also somewhat alters his position. When several of the large planets are together on the same side they draw the sun a certain small distance from his place; then, as they go round to the other side, they gradually attract him back again; so that the stability of the solar system is not disturbed. [PERTURBATION.] That system constitutes part of the Galaxy and is moving to a point in the constellation Her IMG:content-1700.png:[blocks in formation] "Supposing the solar system to have been originally a great revolving nebula of this description condensing to a central sun, and forming from its outer portions smaller ma es, such as the planets and their satellites, or the comets and meteorites, we may expect them to consist principally of the more volatile or the lightest elements, with smaller portions of the le volatile or heavier ones. On arranging the elements of which the earth is composed according to the known or presumed density of the vapors it is found that such is actually the case." Regarding the age of the earth and of the solar system generally, physicists, as represented by Sir Wm. Thomson, Prof. Tait, ., and geologists, led by Prof. Huxley, are at variance. [GEOLOGY, 1. (3).] Nor is there any agreement as to its probable future duration. [COPERNICAN, KEPLER, PTOLEMAIC, .]