Half-hours with the Telescope - Being a Popular Guide to the Use of the Telescope as a - Means of Amusement and Instruction. by Richard Anthony Proctor
page 58 of 115 (50%)
page 58 of 115 (50%)
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recognised as forming a tolerably well-marked small group. The star
Alkes, or [alpha] Crateris, must first be found. It is far from being the brightest star in the constellation, and may be assumed to have diminished considerably in brilliancy since it was entitled [alpha] by Bayer. It will easily be found, however, by means of the observer's star maps. If now the telescope be directed to Alkes, there will be found, following him at a distance of 42ยท5 s, and about one minute southerly, a small red star, R. Crateris. Like most red stars, this one is a variable. A somewhat smaller blue star may be seen in the same field. There is another red star which may be found pretty easily at this season. First find the stars [eta] and [omicron] Leonis, the former forming with Regulus (now lying towards the south-west, and almost exactly midway between the zenith and the horizon) the handle of the Sickle in Leo, the other farther off from Regulus towards the right, but lower down. Now sweep from [omicron] towards [eta] with a low power.[6] There will be found a sixth-magnitude star about one-fourth of the way from [omicron] to [eta]. South, following this, will be found a group of four stars, of which one is crimson. This is the star R Leonis. Like R Crateris and R Leporis it is variable. Next, let the observer turn towards the south again. Above Corvus, in the position shown in the Frontispiece, there are to be seen five stars, forming a sort of wide V with somewhat bowed legs. At the angle is the star [gamma] Virginis, a noted double. In 1756 the components were 6-1/2 seconds apart. They gradually approached till, in 1836, they could not be separated by the largest telescopes. Since then they have been separating, and they are now 4-1/2 seconds apart, situated as shown in Plate 3. They are nearly equal in magnitude (4), and both pale yellow. |
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