For these reasons we would need an almanac to help us keep track of the exact hour when the Big Dipper would be in a given position for every night in the year. But you can always find the Big Dipper any evening in autumn about nine o’clock, by remembering that it is turned right side up as shown in [Figs. 3] and [4]. Again, if you look for the Big Dipper in winter at about nine o’clock in the evening you will find it standing on its handle a little to the east as in [Fig. 9]. In spring about 9 o’clock, it will have moved on round the North Star until it is upside down, as in [Fig. 10], while in summer, at 9, it is hung up by its handle high in the sky, as shown in [Fig. 11]. The four positions of the Big Dipper during the same hours of the different seasons are shown in [Fig. 12], which also shows the four positions of the Big Dipper during each 24 hours.
Fig. 9.—The North Star and Big Dipper in Winter.
By turning the chart round on the board counter-clockwise you will soon come to a point where the Big Dipper of paper stars and the Big Dipper of real stars are in exactly the same position.
Fig. 10.—The North Star and Big Dipper in Spring.
You have, no doubt, noticed that a line joins the two end stars of the Big Dipper and the North Star in [Figs. 3], [4], [10], and [11]. These two end stars of the Big Dipper are called pointer stars, for they point directly to the North Star; that is if we draw a line with the eye through the pointer stars and produce, or continue the line, it will run into the North Star, nearly.
By using these pointer stars it is easy for any one who knows the Big Dipper to be able to find the North Star on any clear night in the year, for the Big Dipper can be seen the year round.
The seven stars which form the Big Dipper are not the brightest stars in the sky by any means, yet each one is a great white sun as large or larger than our own Sun.
