Publisher's Synopsis
Excerpt from Variable Stars of Short Period
The most natural explanation of the variation of a star of short period is that it is due to its rotation around its axis. In the Annals of the Harvard College Observatory, xi. 264, the variation in light of Iapetus, the outer satellite of Saturn, is discussed on this hypothesis. It is there shown that if the axis of revolution is perpendicular to the line of sight, the variation of light, L, may be approximately represented by the formula, L a 6 sin v c cos 0 d sin 2 v 6 cos 2 v a here denotes the mean light, v the angle of rotation, b and c are constants depending on the comparative brilliancy of the two hemispheres, each of which is supposed to be of uniform intensity, but one brighter than the other; d and a depend on a supposed deviation of the body from the form of a solid of revolu tion. This equation may also be written in the form L a m sin (0 a) 1: sin (2 v B), in which a depends upon the angular position of the plane separating the two hemispheres from the line of sight at the epoch from which the variation in light is reckoned; B in like manner depends upon the positions in which the body subtends its largest and smallest discs. Our problem then is to see how far this equation will represent the variation in light of all the stars of the fourth class. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
