22 NATURE-STUDY REVIEW [17:l--Jan., 1921 



side of the triangle beyond the star Vega a distance practically 

 the same as the side of the triangle. Epsilon, a yello'-Adsh star 

 of the fourth magnitude, is one of the famous stars of this family. 

 It is at one angle of the triangle; a sharp eye can divide Epsilon 

 into two stars, and with a glass each of these stars can be seen 

 distinctly as doubles — hence Epsilon is a double, double star. 

 Sheliak and Sulafat are at the angles of the parallelogram farthest 

 from Vega and its triangle. Sheliak is both a double and a 

 variable star; a noted short period variable and one of the ten 

 pear-shaped stars. It has a white light and is a star of the third 

 magnitude. A powerful telescope locates the famous ring nebula 

 between Sulafat and Sheliak. 



By far the most famous star in the constellation of Lyra is the 

 steel blue Vega. It is the most brilliant star of the northern 

 hemisphere. In fact there are only three stars 

 in the whole heavens which surpass Vega in 

 splendor and they are all in the southern skies; 

 they are Sirius, Canopus and Alpha Centauri. 

 Capella and Arcturus are its only close rivals in 

 the northern hemisphere. In the autumn as 

 Vega and her accompanying stars go down in the 

 northwest Capella comes up in the northeast. 

 These two rivals are usually seen in the heavens 

 at the same time. At this time of the year 

 Arcturus is below the horizon. Vega, or the Harp 

 Vega and her train Star as it is sometimes called, is also termed the 

 of five stars Arc-light of the sky. Some 14,000 years ago 

 Vega was the north polar star and it is calculated that 1 1,500 years 

 hence it will again occupy that position. Together with the other 

 stars of the constellation Lyra, it occupies the region of the heavens 

 towards which our solar system is travelling — the Apex of the 

 Sun's Way being probably fairly near the fourth magnitude star 

 Delta. Vega is 35 light years distant from us and is supposed to 

 give 90 times as much light as our sun. It belongs to the Syrian 

 type of stars, while Capella and Arcturus are of the solar type; 

 hence Vega is supposed to be much more rarefied and less hot 

 than its rival companions. It is travelling toward our solar 

 system at the rate of about ten miles per second; still more than 

 half a million of years must elapse before Vega and our sun shall 

 pass each other. 



