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THE GUIDE TO NATURE 



southern heavens from Scorpio to the 

 Lesser Dog. Above the Zodiac and 

 bordering it on the north is the train 

 of beautiful constellations from Lyra 

 to Auriga which will well repay 

 study, especially the western part of 

 it, in which there are several fainter 

 and less generally known star groups. 



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The May Stars. 



The constellation of the Balance, 

 which closely follows Virgo, is at 

 once recognized by the two bright 

 stars at E and D, although there are 

 fifty-three stars visible without tele- 

 scopic aid which are included within 

 the borders of this constellation. The 

 four stars D, E, F and H, which form 

 a quadrilateral in Libra, are all of in- 

 terest. The stars at D and E are seen 

 to be double even in a pair of opera 

 glasses, while that at H also is a 

 double, showing a fine contrast of col- 

 or, but as the companion is of the 

 ninth magnitude this can only be seen 

 with a small telescope. 



The star at E is the only naked eye 

 star in the heavens which has a decid- 

 edly greenish color. It is thought that 

 this star has varied in brightness, 

 since two thousand years ago it was 

 described as the brightest star of all 

 in the combined constellation of the 

 Scorpion and the Balance (the Bal- 

 ance was formerly a part of the con- 

 stellation of the Scorpion) while now 

 Antares, the brightest star of Scorpio, 

 is nearly five times as bright as the 

 star at E. Later the two stars were 

 described as being of equal brightness. 

 No change in brightness has been ob- 

 served, however, since accurate mea- 

 sures have become possible. 



The star at K is a well-known vari- 

 able. Two-thirds of its light is cut 

 off every thirty-two hours by the pas- 

 sage of a dark companion between us 

 and it, the companion revolving about 

 the principal star in this time. It is 

 thus exactly similar to the more strik- 

 ing eclipsing variable, Algol, at L. Fig- 

 ure I. If a straight line be imagined 

 drawn from the star at H to that at 

 E and extended a distance about equal 

 to its own length it will end in a strik- 

 ing, compact cluster of faint stars, 

 very much condensed toward the cen- 

 ter. About sixty of these faint stars 

 are variables of a certain kind, from 



which we may obtain the approximate 

 distance away of this and similar clus- 

 ters. A short distance above and to 

 the east of this cluster there is an in- 

 teresting double star, but neither of 

 these objects is well seen except in a 

 telescope of at least three inches aper- 

 ture. 



The reader should not fail to ex- 

 amine the beautiful little group of 

 Coma Berenices, now exactly on the 

 meridian, high in the south. On moon- 

 less nights, such as we shall have dur- 

 ing the first twelve days of the month, 

 the sky may here be seen with an opera 

 glass to be covered with a most deli- 

 cate, filmy network of stars which, as 

 has been pointed out, if removed a few 

 thousand light years farther away 

 would appear to us as a faint star clus- 

 ter or even as a nebula. Though so 

 faint many of the separate stars of this 

 constellation were given names two 

 thousand years ago. It was then call- 

 ed Ariadne's Hair (Ariadne's Crown 

 being our Corona), but from 234 B. C. 

 it was known as Berenice's Hair, Ber- 

 enice being the sister of one of the 

 rulers of Egypt. 



There are many interesting double 

 stars here and several star clusters and 

 nebulas which can be found by the 

 help of a star atlas. This small but 

 densely filled region of the sky will 

 well repay exploration with a small 

 telescope. Having become somewhat 

 familiar with the larger constellations 

 and the brighter objects of the sky, 

 the reader will find it much better to 

 thoroughly explore a small region, 

 such as this, than to turn over the 

 heavens from one object to another. 

 He thus makes the small part of the 

 heavens, as it were, his own, and he 

 becomes familiar with the use and lim- 

 itations of his instrument. Many most 

 beautiful objects may not be seen until 

 after many evenings' trial, for he will 

 soon learn that the transparency of 

 the air and the "seeing" varies remark- 

 ably from night to night. Of course, 

 having minutely examined one, region, 

 he may turn to another and thus grad- 

 ually acquire a detailed knowledge of 

 the face of the heavens as it is revealed 

 in his instrument. 



The Pole of the Milky Way is in al- 

 most the exact center of Coma Bere- 

 nices. As this is nearly overhead, the 



