Sky Study 



899 



Qrion and the Dog Stars. 



B, Betelgeuse; R, Rigel; S, Sirius, the Great Dog Star; 

 P, Procyon, the Little Dog Star. 



Sirius is a comparatively 

 young star, and is estimated 

 by Proctor to have a diameter 

 of about twelve million miles 

 or fourteen times that of our 

 own sun; it is only eight and 

 one-half light-years away from 

 us and is the most celeorated 

 star in literature. The an- 

 cients knew it, the Egyptians 

 worshipped it, Homer sang of 

 it, and it has had its place in 

 the poetry of all ages. 



Procyon, (pro'-se-on) the 

 Little Dog Star, was so-called 

 perhaps because it trots up the 

 eastern skies a little ahead of 

 the magnificent Great Dog 

 Star; it gives out eight times 

 as much light as our sun, and is only ten light-years away from us. It has a 

 fainter companion about three or four degrees to the northwest of it. 



LESSON CCXXIX 

 THE Two DOG STARS 



Leading thought The Great Dog Star, Sirius, is the most famous of all 

 stars in the literature of the ages. The Two Dog Stars were supposed by 

 the ancients to be following the great hunter, Orion. 



Method Draw upon the board from the chart shown 011 this page, the 

 constellation of Orion with Sirius and Procyon. Ask the pupils to note 

 that after Orion is well up in the sky a straight line drawn through Orion's 

 belt and dropping down toward the eastern horizon ends in a beautiful 

 white star, which is Sirius. And that if we draw a line from Betelgeuse to 

 Rigel from Rigel to Sirius and then draw lines to complete a quadrangle, we 

 shall find our lines meet at a bright star just a little too far away to make 

 the figure a square, but making it somewhat kite-shaped instead. This is 

 the Little Dog Star, Procyon, and it has a twin star near it. After giving 

 these directions let the children make the following observations: 



1 . How do you find Sirius ? Which rises first, Orion or Sirius ? 



2 . What color is Sirius ? Judging from its color what stage of develop- 

 ment do you think it is in ? 



3 . Try and find out how large Sirius is compared with our sun and how 

 near it is to us. 



4. Why is Sirius called the Great Dog Star' Is the Little Dog Star 

 nearer to the North Star than Sirius? Which is the brighter, the Greal 

 Dog Star or the Little Dog Star? Can you see any fainter star near 

 Procyon ? 



5. Why is Procyon called the Little Dog Star? 



6. Make a chart showing Orion and the two Dog Stars. 



