OF TIE FIXED STARS.
The fixed stars are so called, because they are observed not to change their places in the heavens, as the planets do. They appear of an infinite variety of sizes; yet, for convenience, it is usual to class them into six or seven magnitudes ; thus, they are called stars of the first, second, &c. magnitude. To the naked eye they appear innumerable, but this is only the consequence of their being scattered in so confused a manner, and our not being able to see them all at one view. The whole number of stars visible to the naked eye is about 3186. But seldom above one-third of that number can be seen at one time. From the earliest ages they have been di vided into groups, or constellations, which have been called by the names of various animals and objects, from a supposed re semblance to them ; such as the Great Bear, the Little Bear, the Swan, &c. The fixed stars are placed atadistance from us so great, that it cannot be ascertained by any means yet known : hence, they must shine by their own light, and not by the light which they receive from our sun, as the planets do. Though it has been for merly mentioned that the relative situa tions of the fixed stars do not vary, yet in the course of several ages some variations have been observed among them. Some of the larger stars have not the same pre cise situations that ancient observations attribute to them, and new stars have ap peared, while some others, which have been described, are now no longer to be found. Some stars are likewise found to have a periodical increase and decrease. Many of the fixed stars, upon examination with the telescope, are found to consist of two. Besides the phenomena already mentioned, there are many nebula, or parts of the heavens, which are brighter than the rest. The most remarkable of these is a broad irregular zone or belt, called the Milky-way There are others much smaller, and some so small, that they can be seen only by telescopes. If the telescope be directed to these ne bula', they are resolvable into clusters of stars, which appear as white clouds in in- struments of less force. Dr. Herschel has rendered it highly probable, both from observation and well grounded con jecture, that the starry heavens is replete with these nebula or systems of stars, and that the Milky-way is that particular nebula in which our sun is placed. Rea soning analogically from the circum stances with which we are acquainted, we may deduce, that the universe consists of nebula or distinct systems of stars ; that each nebula is composed of a prodigious number of suns or bodies, that shine by their own native splendour ; and that each individual sun is destined to give light to numbers of worlds that revolve about it. What an august, what an amaz ing conception does this give of the works of the Creator ? Instead of one world and one sun, we find thousands and thousands of suns ranged around us at immense distances, all attended by innumerable worlds, all in rapid motion, yet calm, re gular, and harmonious, invariably keeping the paths prescribed them ; and these worlds peopled with myriads of intelli gent beings, formed for endless pro res sion in perfection and felicity. We shall now, in the form of a table, give the names of the constellations, and the number of stars observed in each by different astro nomers.
Several stars observed by the ancients are now no more to be seen, but are de ed ; and new ones have appeared, which were unknown to the ancients. Some of them have also disappeared for some time, and again become visible. We are also assured, from the observations of astronomers, that some stars have been observed which never were seen before, and for a certain time they have distin guished themselves by their superlative lustre ; hut afterwards decreasing, they vanished by degrees, and were no more to be observed. One of these stars being
first seen and observed by Hipparchus, the chief of the ancient astronomers, set him upon composing a catalogue of the fixed stars, that by it posterity might learn whether any of the stars perish, and others are produced afresh. After seve ral ages, another new star appeared to Tycho Brahe, and the astronomers who were contemporary with him ; which put him on the same design with Hipparchus, namely, the making a catalogue of the fixed stars. Of this, and other stars, which have appeared since that time, we have the following history by Dr. Halley. "The first new star in the chair of Cassi opeia was not seen by Cornelius Gemma on the 8th of November, 1572, who says, he, that night, considered thatpart of the heaven in a very serene sky, and saw it not ; but that the next night, November 9, it appeared, with a splendour surpassing all the fixed stars, and scarce less bright than Venus. This was not seen by Ty cho Brahe before the 11th of the same month ; but from thence he assures us that it gradually decreased and died away; so as in March, 1574, after sixteen months, to be no longer visible ; and at this day no signs of it remain. Its place in the sphere of fixed stars, by the accurate ob servations of the same Tycho, was 0' 17' a lmt2* cr, with 30° 45' north latitude. Such another star was seen, and observ ed, by the scholars of Kepler, to begin to appear on September 30, St. Vet. anno 1604, which was not to be seen the day before ; but it broke out at once, with a lustre surpassing that of Jupiter, and like the former, it died away gradually, and in much about the same time disap peared totally, there remaining no foot steps thereof in January, 1605-6. This was near the ecliptic, following the right leg of Serpentarius ; and by the observa tions of Kepler, and others, was in 7' 28° 00' a Pp, with north latitude 1° 56'. These two seem to be of a distinct spe cies from the rest, and nothing like them has appeared since. But between them, viz. in the year 1596, we have the first ac count of the wonderful star in Collo Ceti, seen by David Fabricius on the 14th of August, as bright as a star of the third magnitude, which has been since found to appear and disappear periodically ; its period being precisely enough seven re vol itions in six years, though it returns not always with the same lustre. Nor is it ever totally extinguished, but may at all times be seen with a six feet tube. This was singular in its kind, till that in Collo Cygni was discovered. It precedes the first star of Aries 1° 40', with 15° 57' smith, latitude. Another new star was first discovered by William Jansonius in the year 1600, in Pectort or rather in Eductione Colli Cygni, which exceeded not the third magnitude. This, having continued some years, became at length so small, as to be thought by some to have disappeared entirely ; but in the years 1657, 1658, and 1659, it again arose to the third magnitude ; though soon af ter it decayed by degrees to the fifth or sixth, magnitude, and at this day is to be seen as such in 38' a lma * with 55° 29' north latitude. A fifth new star was first seen by Hevelius in the year 1670, on July 15, St. Vet, as a star of the third magnitude ; but by the beginning of October wasscarce to be perceived by the naked eye. In April following it was again as bright as before, or rather greater than of the third magnitude, yet wholly disap peared about the middle of August.