TO KNOW THE STARRY HEAVENS 



95 



Great Square of Pegasus have all ap- 

 peared in the east. 



A very beautiful region for explora- 

 tion and study is that which lies within 

 the borders of the constellation Cygnus, 

 or the Northern Cross, now high in the 

 evening sky. The star at A is perhaps 

 the most beautiful double star in the 

 heavens with a small aperture, the larg- 



which, from the immense amount of 

 mathematical research which has been 

 devoted to it, is well known to every as- 

 tronomer. This pair is called "Sixty- 

 one Cygni" and has the distinction of 

 being nearer to us than any other known 

 star north of the Celestial Equator. The 

 light from this pair of suns requires bnt 

 eight vears to reach us, so that Sixtv- 



SOUXM 



Figure 1 Tlic Constellations on August 1 at 9 P. M. 

 (If facing south, hold the map upright; if facing East hold east below; 

 if facing west, hold West below; if facing north, hold the map inverted.) 



er star being of a golden color and the 

 smaller one blue. The star at C is a very 

 similar but more difficult double, while 

 that at D is a double presenting an only 

 slightly less beautiful contrast in color, 

 but in which the colors are far more un- 

 usual, the larger star being white and 

 the smaller one of a lilac tint. If there 

 are any worlds in this strange system, 

 the dwellers upon them thus see a white 

 sun and a lilac sun rise every day ; in 

 fact, it might always be day on so 

 strangely situated a world, because, per- 

 haps, one of their suns is always to be 

 seen in their sky. 



At the position E there is an incon- 

 spicuoiis sixth magnitude pair of suns 



one Cygni is at almost exactly the same 

 distance aw^ay as the bright Dog star 

 Sirius. 



The variable star at B, which the 

 reader may have noticed when it was a 

 bright, naked-eye object, is now of near- 

 ly the eleventh magnitude and is daily 

 growing fainter. This strange sun thus 

 oscillates from brightness to faintness 

 continually, the period being 406 days ; 

 though for some cause, as unknown to 

 us as the cause of^the variability itself, 

 this period has recently been growing 

 longer. 



Around the star at F there is a won- 

 derful stream of stars, while between 

 this and the star at H is the curious va- 



