THE SUN AND OTHER, STARS 



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The sun, with all its planets, is moving in the direction 

 of Vega at the rate of about 400,000,000 miles a year, but 

 the distance of this star is so enormous that no appreciable 

 change in its brightness will be produced by this motion in the 



FIG. 135. A gaseous nebula called "North America " 



This peculiarly shaped nebulous mass lies in the Milky Way. Photograph by the 

 Yerkes Observatory 



next ten thousand years. The exact distance of Vega from 

 the earth is not known, but it is thought to be more than 

 3,000,000 times as far as the distance from the earth to the 

 sun. An interesting fact about Vega is that in twelve thou- 

 sand years it will be our Pole Star. This does not mean that 



