comstock] THE BEGINNING OF STAR STUDY 391 



see. Sky photography shows us that there are more than three 

 thousand stars in this little constellation; and astronomers believe 

 that it is a great star system now being developed. These stars 

 which look so close together to us are so far apart that our own 

 sun and all its planets could roll between them unnoticed. It 

 requires several years for light to travel from one of these stars 

 in the Pleiades to another, and the whole constellation is so far 

 away from us that we cannot estimate the distance, but we know 

 that it takes light several hundred years to reach us from them. 

 The following questions should be asked: 



How many stars can you see in the Pleiades 1 



How many stars can you see in the Hyades? Make a sketch 

 of the Hyades showing Aldebaran. 



THE TWO DOG STARS 



Make a map of Orion on the board and extend the line X through 

 the belt toward the horizon. This line will reach a very brilliant 

 star, which is the Big Dog Star, Sirius. Then draw lines yy 1 

 joining Betelgeuse, Rigel, and Sirius and complete the kite-shaped 

 figure by linsey y 2 y 3 which will meet in Procyon, The Little Dog 

 Star. The following questions should be asked after the pupils 

 have observed these two stars. 



Which rises first, Orion or Sirius ? What color is Sirius ? Why is 

 Sirius called the Big Dog Star' 



Is the Little Dog Star nearer to the Pole Star than Sirius? 

 Which is brighter, the Great Dog Star or the Little Dog Star? 



Sirius is the most beautiful of the stars in our skies; it shines 

 with ever changing color, blue, rosy and white. Sirius is a com- 

 paratively young star and has a diameter about 14 times as great 

 as that of our own sun. It is eight and one-half light years away 

 from us. Perhaps no star of our sky is so celebrated in ancient 

 and modern literature as Sirius. Homer mentions it and it has 

 had a place in the poetry of the ages. Procyon, The Little Dog 

 Star, probably earned its name because it trots up the eastern sky 

 just a little ahead of the Great Dog Star, quite like a little dog 

 in its habits. It gives out eight times as much light as our own sun 

 and is only ten light years away from us. Its companion or twin 

 star, is not so brilliant. 



Ask the pupils to join line m, drawn through the pointers of the 

 Dipper to the Pole Star on another line m, at right angles to this 



