Stellar system

“ The whole mass of the stellar system exerts a gravitational influence on the motion of each star in the system, and the individual stars revolve around the center of mass of the system in their elongated orbits. One star stream comprises all those stars moving away from the center, and the other stream all those stars moving toward the center. We can not doubt that the motions of the individual stars are influenced by the gravitational attractions of the stellar system and of the group of stars nearest to them ”

“ It will be seen from the above discussion that stellar photometry in its broadest sense furnishes the means of attacking, and perhaps of solving, the greatest problem presented to the mind of man—the structure and constitution of the stellar universe, of which the solar system itself is but a minute and insignificant molecule. ”

“ They are exhibited only by those of the ninth magnitude, or fainter; for with them sets in a significant crowding upon its condensed parts, attended by a scarcity over its comparative vacuities. Counts by magnitudes have, besides, made it clear that the stars, in portions of the sky removed from the Milky Way, thin out notably before the eleventh magnitude is reached; so that, outside the galactic zone, the stellar system is easily fathomed. ”

“ Now if the sun is a star, then, according to our First and Second Rules of Philosophy, every star ought also to be the centre of a stellar system and the centre of two aetherial motions, that is, the Centrifugal and Centripetal forces, due to the pressures and tensions of the Aether medium. Further, every stellar system would be composed of exactly similar bodies to those which compose our solar system, as planets with their attendant satellites, together with meteors and comets ”

“ As has already been mentioned, the neighbourhood of the centre of a stellar system is a scene of comparative rest. In the solar system we see the planets travelling faster and faster, the nearer they are to the great ruling centre of the scheme ”

“ If we pass from sun to star, the triumph of the spectroscope has been everywhere complete and significant. As the spectroscopic survey of the stars grew toward completeness, it became evident that the swarming hosts of the stellar universe are in constant motion through space, not only athwart the line of vision as their proper motions had long disclosed, but some stars are swiftly moving toward our solar system and others as swiftly from it. ”

“ Old theories are tested and newer ones often perfected by the detection of some slight and previously [38] unsuspected alteration upon the face of the sky. The interpretation of such changes is the most difficult task of science; it has taxed the acutest intellects among men throughout all time.
If, then, changes can be seen among the stars, what are we to think of the most important change of all, the blazing into life of a new stellar system? Fifteen times since men began to write their records of the skies has the birth of a star been seen. ”

“ The vast problem of the arrangement and relations of the millions of stars forming the Milky Way was shown to be capable of experimental treatment, and of at least partial solution, notwithstanding the variety and complexity seen to prevail, to an extent previously undreamt of, in the arrangement of that majestic system. The existence of a luminous fluid, diffused through enormous tracts of space, and intimately associated with stellar bodies, was virtually demonstrated, and its place and use in creation attempted to be divined by a bold but plausible conjecture. ”

“ Speaking in a general way, we may say that computations pertaining to the orbital revolutions of double stars, as well as the bodies of our solar system, are to a greater or less extent of the classes we have described. The principal modification is that, up to the present time, stellar astronomy has not advanced so far that a computation of the perturbations in each case of a system of stars is either necessary or possible, except in exceptional cases. ”

“ Such a discussion must naturally be the first step in the analysis of the stellar atmosphere. When the more general results of observation have been reduced, in some measure, to an orderly system, it becomes possible to consider special problems involving stars or groups of stars, which lie outside the system, or which, though included in the system, display definite abnormalities. ”

“ But the difficulty is that the part of the stellar universe which we mainly survey is a local condensation or star-cloud forming part of a much greater system. In certain directions in the sky our telescopes penetrate to the limits of the system, but in other directions the extent is too great for us to fathom. The Milky Way, which on a dark night forms a gleaming belt round the sky, shows the direction in which there lie stars behind stars until vision fails. ”

“ If the former, then, according to the theory that stellar heat had its origin in collision, it is presumptive evidence that space is occupied by dark bodies far more numerous and massive than the luminous ones which the telescope reveals. ”

“ The theory starts with the assumption that the greater part of the energy possessed by the universe exists or is stored up in the form of the motion of stellar masses. The amount of energy which may thus be stored up is startling to contemplate. Thus a mass equal to that of the sun, moving with a velocity of 476 miles per second, would possess, in virtue of that motion, energy sufficient, if converted into heat, to maintain the present rate of the sun’s radiation for 50,000,000 years. ”

“ The differential effects of pressure are too small to detect in stellar spectra by present means, and there is no known method of eliminating them. We have no recourse but to assume that the stellar lines, neglecting the effect of radial motion, are in identically the same position as the solar lines and the laboratory lines of the elements. Whether the lines in the blue stars are produced under lower pressure than those in the sun, and the lines in the red stars under greater pressure than those in the sun, remains unknown, but this is not impossible. ”

“ They involve investigations of critical potentials, spectral classification, stellar temperatures, the abundance of elements, and the far-reaching theories of thermal ionization as developed in the last few years by Saha and by Fowler and Milne. Some problems of special interest to chemists and physicists are considered, and subjects intimately bound up with inquiries concerning stellar evolution come under discussion. ”

“ It will be only when the two bodies, coming from contrary directions, collide with equal momentum that the entire motion will be stopped. But in the case of stellar masses moving, as it were, at random in every direction this is a condition which will but rarely occur. Accordingly, in most cases the resulting stars will have more or less motion. In short, the stars should, according to the theory, be moving in all directions and with all varieties of velocity. ”

“ Matter can be studied terrestrially in small quantities only, and when a laboratory source is used in obtaining a spectrum, all the contributing material is collected into a very small region. With the stellar source it is quite otherwise. An enormous mass of matter, spread over a very large region, gives rise to the spectrum, and probably widely different physical conditions prevail at the origin of light of different wave-lengths. The present chapter contains a brief survey of the chief components which go to make up the stellar spectrum. ”

“ This body, if only composed of atoms, may easily be so fine and subtle as to pass practically unchanged through ordinary gross matter—the walls, for instance, and other obstacles that surround us. (At this moment there is an astronomical theory current that the stellar universe consists of two vast star-systems which are passing in nearly opposite directions right through each other.) If composed of electrons its subtlety and pervasive powers must be much greater. ”

“ The spectrum of a star nearly always consists of a continuous background, in which the energy distribution corresponds more or less to that of a black body, and of absorption and emission lines and bands. The observed stellar spectrum is the integrated contribution from all parts of the disc, the unlined portion representing radiation that passes undisturbed from the photosphere through the reversing layer, and the light within any individual absorption line coming from the greatest depth in the reversing layer that can be penetrated by light of the corresponding frequency. ”

“ 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. ”

“ But there are other solar systems within our astral systems, which are as yet in a less advanced state, and even some quantities of nebulous matter which have scarcely begun to advance towards the stellar form. ”

“ Another star shows the lines of various metals more conspicuously, indicating that the glowing vapours of such elements, iron, copper, mercury, tin, and so forth, either hang more densely in the star's atmosphere than in our sun's, or, being cooler, absorb their special tints more effectively. But speaking generally, a stellar spectrum is like the solar spectrum. ”

“ Thus, the molecules strike a balance, as it were, against each other so that the different parts of the gas accumulations57 shortly are brought to rest relative to each other. The irregular gas mists around the Milky Way form therefore a continuous whole. A different condition obtains in regard to condensed stellar bodies such as the stars. They may in the densest throng move during billions of years before they collide; but they might on the other hand enter nebulous masses and thereby suffer gradual retardation. We now refer to stars moving outside of the vapour clouds. ”

“ When we bear in mind that, in addition to these various contrasts, the planets and satellites also differ in respect to their distances from each other and their primary; in respect to the inclinations of their orbits, the inclinations of their axes, their times of rotation on their axes, their specific gravities, and their physical constitutions; we see what a high degree of heterogeneity the solar system exhibits, when compared with the almost complete homogeneity of the nebulous mass out of which it is supposed to have originated. ”

“ For that reason the condenser, and the great cage-switch of the condenser, were guarded always by hovering cones, to prevent its being turned off before the right moment.
"Since then they have kept the great gravity-condenser in unceasing operation, and their dark star has swept in toward the Galaxy's edge in a great curve. Back in our own solar system I saw and understood what would be the result of that inward curve, and so we came here—and were captured. ”

“ Our knowledge of binary star systems brings us to what may be regarded as the threshold of the fabric of the heavens. For it is known that other systems exist into the construction of which numerous stars enter. These form intricate and complex stellar arrangements, in which the component stars are physically united and retained in their orbits by their mutual attraction. ”

“ Ultimately it may be that the consistency of the findings in different branches of astrophysics will form a basis for a more general verification of physical laws than can be attained in the laboratory; but at present, terrestrial physics must be the groundwork of the study of stellar conditions. Hence it is necessary for the astrophysicist to have ready for application the latest data in every relevant branch of physical science, realizing which parts of modern physical theory are still in a tentative stage, and exercising due caution in applying these to cosmical problems. ”

“ The impact theory does not rest upon a purely hypothetical basis. The cause to which it appeals has a real existence. The point of uncertainty is whether the cause actually produces the effect which is attributed to it. We know from observation that there are stellar masses, some of them probably larger than our sun, moving through space with enormous velocities in all directions. ”

“ The paths of the planets and comets round the Sun, and of the satellites round their planets, are called their ORBITS.
Those stars which always appear in the same situation in relation to each other are called Fixed Stars. About 1000 can be seen at once by the naked eye, and by the help of the telescope many millions may be seen. Their sizes are little known, but probably some of them are many million times larger than the earth. They are not considered a part of our Solar System, but are supposed to be Suns of other systems, round which other planets revolve. ”

“ The recent advance of astrophysics has been greatly assisted by the development, during the last decade, of atomic and radiation theory. The claim that it would have been possible to predict the existence, masses, temperatures, and luminosities of the stars from the laws of radiation, without recourse to stellar observations, represents the triumph of the theory of radiation. It is equally true that the main features of the spectra of the stars could be predicted from a knowledge of atomic structure and the origin of spectra. ”