Page:Astronomy for Everybody.djvu/334

East of Alpha is a white mass like a httle cloud. With a small telescope, even with a good field glass, we see this mass to be a collection or cluster of small stars. It is the Great Cluster of Perseus and, in the figure of the constellation, forms the hilt of the hero's sword.

In a sort of offshoot toward the south (or southeast as the constellation is now situated) lies a row of three stars. The middle and brightest of these is the wonderful variable star, Algol, whose changes will be described in a later chapter. It is also called Beta Persei.

Below Perseus, the first large constellation is Auriga, the Charioteer. It is marked by Capella, the Goat, a star of the first magnitude and one of the brightest now above the horizon—indeed, one of the four or five brightest in the sky. But it has no other striking stars.

In the southeast are Aldebaran and the Pleiades, which will be described later. Meanwhile let us follow the course of the Milky Way from the zenith toward the west.

The first collection of bright stars west of Cassiopeia is now Cygnus, the Swan, lying centrally in the Milky Way. Five stars are arranged somewhat in the form of a cross and mark the body, neck, and extended wings of the bird. The brightest of the group is Alpha Cygni, or Deneb, nearly, but not quite, of the first magnitude.

Low and to the right of Cygnus, and a little outside of the Milky Way, is the constellation Lyra, the Harp, marked by the beautiful and very bright bluish star, Vega. It has no other star of greater magnitude than the third, but what it has will repay careful study.