Next we are to become acquainted with the glory of our winter skies, the constellation of Orion, Fig. 94. I dare say many of my readers are already familiar with the well-known twin stars which form the belt of Orion, but if not, they will be able to recognize it by the help of the groups already learned. Imagine a line drawn from the Pole Star through Capella, and then produced as much further again, and we shall be conducted into the precincts of Orion. This group lies on the equator, and, consequently, it is equally familiar to southern astronomers and to those of the north. It can be best seen by those who observe it from or near the equator.
The brightest star in Orion is known either as α Orionis or as Betelgeuze, by which name it is represented in the figure. This star is of the first magnitude, and so is Rigel on the opposite side of the belt. The three stars of the belt and the two others, γ and κ, at which they point above and below, are of second magnitude.
The owner of a telescope finds especial attractions in this constellation. Notably among the subjects which will interest him is the Great Nebula, the position of which is indicated in our figure. Under the middle of the belt are a few stars, around which is a hazy light that is perceptible with the smallest telescopic aid. Viewed by instruments of adequate proportions, these have developed into a marvellous nebula of glowing gas, attaining to dimensions so vast that no one has yet ever attempted to estimate them.
The vicinity of Orion is also enriched with some of the most interesting stellar objects. Follow the line of the belt upwards to the right, and your eye is conducted to a ruddy first magnitude star named Aldebaran, in the constellation of the Bull. This is a pleasing object, which the beginner will sometimes be apt to confuse with the planet Mars, to which, under certain circumstances, it certainly bears a resemblance. Another very pleasing little group, known as the Hyades, will be found near Aldebaran. If the line of the belt of Orion be carried down to the left, it will be found to point to Sirius, or the Dog Star.
You will find it an interesting occupation to make for yourself maps of small parts of the heavens. First copy out the chief stars in their proper places from the star atlas, and then fill in the smaller stars with your own observations. Try first on some limited region of the heavens; take the figure of Cassiopeia, for instance, or the Square of Pegasus, and see if you can produce a fair representation of those groups by marking in the stars that your instrument will show you; or take the Pleiades and make a tracing of the principal stars of the group from the sketch that we have given (Fig. 89), then take an opera-glass and fill in as carefully as you can all that it will show. I can assure you that you will find a little definite work of this kind full of interest and instruction.