Изображения страниц
PDF
EPUB

off by the clouds, which are SO common in this climate of ours. Draco and Cepheus and a few more constellations near them behave in a similar manner, and earn for themselves the term of "circumpolar constellations."

The constellation next in order of prominence in the evening sky is that of Orion. Unlike those we have been describing, it can only be seen during certain months of the year. About the middle of January three brilliant stars in a line can be seen in the south at ten o'clock. The configuration is so conspicuous that a glance upward is all that is required to recognise it. To the matterof-fact Englishman the group is known as the YardStick, but astronomers, following the lead of Ptolemy, name it the Belt of Orion (Fig. 2). A glorious constellation this, and one which has only to be seen to be remembered. Four bright stars in the form of an oblong surround the belt and mark different parts of the body of the giant Orion, the two above the belt indicating the positions of his two shoulders, whilst the two below locate his right knee and left foot respectively. Hanging from the belt is Orion's sword, represented in the sky by three small stars.

Con

Orion's Belt shall guide us to other stars. tinue its direction upwards to about five times its length, and a bright star of a ruddy colour will be met. This is Aldebaran, the brightest star in the constellation of the Bull (Taurus). Carry the line still further, and that beautiful cluster of stars known as the Pleiades will be seen. Six stars can easily be distinguished with the naked ten have been counted in the cluster by persons

eye, and as many as

gifted with keen vision.

A small telescope will reveal

about a hundred stars, and nearly three thousand have been found on a photograph of the group.

[graphic][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed]

FIG. 2.-Some constellations visible when looking south at 10 P.M. about the middle of January. The names of stars are in small type.

By again using Orion's Belt, we can find the constellation of the Great Dog (Canis Major). The line of stars points downwards to an unmistakable object, -the brightest of all that bespangle the sky, the Dog

Star-Sirius. To the north-east of Sirius, another bright star, Procyon or a Canis Minoris, will be found. Betelgeuse (a Orionis), Sirius, and Procyon form a triangle, having sides of equal length. They are all bright stars, so there should be no difficulty in finding them.

The constellation Gemini or the Twins next claims our attention. It lies to the north-east of Orion. A line from Procyon carried towards the tail of the Great Bear passes near the two chief stars, Castor and Pollux, in the constellation. Pollux is about the same distance north of Procyon that Procyon is east of Betelgeuse, whilst Castor lies slightly to the north-west of his brother.

Leo, the Lion, is the chief constellation visible in the south at ten o'clock about the middle of March. In outline it bears a resemblance to an Egyptian sphinx. The Pointers produced backwards lead to this figure (Fig. 3). Regulus, the brightest star in the constellation, lies near the place where the directing line cuts the body of the Lion. Above it occurs a line of stars, curved like the blade of a sickle. Indeed, these stars form a very good sickle, with Regulus at the end of the handle. A line from Procyon, through Regulus, passes over Denebola, a fairly bright star in the Lion's tail.

The constellation Virgo, the Virgin, lies south and east of the Lion. A line drawn in a south-east direction from Denebola reaches Spica, the principal star in Virgo. There should be little difficulty in finding this object, for there are no other bright stars in the neighbourhood. Spica can also easily be found from the Great Bear configuration; for if the line

connecting the stars a and y in this constellation be produced southwards in a slightly curved form, it will reach the required object.

The end of May sees the constellation Bootes due

[graphic][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed]

FIG. 3.-Some of the constellations visible during summer. of stars are in small type.

The names

south at ten o'clock. Its principal star, Arcturus, is almost as brilliant as Sirius, but of a different colour. By continuing the curve of the tail of the Great Bear the star is at once found. Another guide is formed by drawing a line from Regulus through Denebola,

and producing it until the reddish-coloured star is

reached. A large equilateral triangle can be recognised in the heavens, with its corners marked by Spica, Denebola, and Arcturus, the last-named star being situated at the northern apex of the figure. In a line with the last two stars in the Great Bear's tail, and at a distance about twice as great as that separating them, y Bootes will be found. This star forms one of the corners of a diamond-shaped figure composed of stars in Bootes.

[graphic]

FIG. 4. Relative positions of the

constellations

and Aquila.

North-east of Bootes occurs a constellation which has been named the Northern Crown, or Corona Borealis. The stars in this group are arranged in the form of a semicircle, and are thus rendered easy of recognition. To the north-east again occurs the constellation Hercules, which, though wide in extent, contains no very bright stars.

Some fine constellations Cygnus, Lyra, can be seen when looking towards the south at ten

o'clock in the months of August and September

« ПредыдущаяПродолжить »