Читать книгу The Circle of Knowledge: A Classified, Simplified, Visualized Book of Answers - Various - Страница 38

We shall now study the so-called fixed stars, those stars, namely, which preserve the same relative position and configuration from night to night, only varying, and that with perfect regularity, in the times at which they reach the meridian. For this reason they have been known from the dawn of astronomy as fixed stars, in contrast with the planets or wandering stars.

The observer who watches the nightly changes in the sky with close attention will soon perceive that all these fixed stars appear to move in circles or parts of circles. Some of them describe larger circles than others, and the further south a star is when it passes the meridian, the larger circle will it describe.

It cannot be too often repeated that this motion of the stars is only apparent, being due to the real rotation of the earth, along with the observer on its surface, in the contrary direction. It is estimated that there are about three thousand stars visible to the naked eye in our latitude, though not all these are visible at the same time, many of them being below the horizon, while others are elevated in the sky at different times and seasons.