190 GETTING ACQUAINTED WITH THE STARS 



telescope shows us bodies whose light is too dim to be seen 

 with the unaided eye. But if we were to expose a photo- 

 graphic plate behind a telescope lens for several hours 

 under the same space in the sky, we would be amazed 

 to find when the plate is developed that not thousands 

 but hundreds of thousands of stars will appear where we 

 saw only a few with our naked eye. The reason for this 

 is that the chemicals on the plate are sensitive to rays 

 of light too weak to register in the human eye, even when 

 we look through the telescope. 



The Astronomer's Yardstick. When we look up at 

 the stars, we realize that some are much larger and some 

 much brighter than others, but all look to be very far 

 away. As a matter of fact, some are very much farther 

 away than others. Some appear nearer because they 

 are more brilliant. Astronomers tell us that the nearest 

 fixed star 1 is over 25,000,000,000,000 miles away. Light 

 travels a little over 186,000 miles a second. In a year 



Solbelman Syndicate 



This shows a portion of the sky as seen through a large telescope. How many 

 of these stars do you think you could see with the naked eye ? 



1 Proxima Centauri. 



