TO KNOW THE STARRY HEAVENS 



535 



almost to Sirius, though the star mark- 

 ing the end of the tail of the Water- 

 snake has not yet risen above the 



ground. 



***** 



The April Stars. 



There is no better time of the year 

 than this for the student to become 

 thoroughly acquainted with the beauti- 

 ful constellation Leo which is now on 

 the meridian in its highest position in 

 the heavens. Even to the naked eye 

 the region from the eastern horizon to 

 the meridian is a most beautiful and 

 interesting sight, and though on the 

 whole the star groups now there are 

 rather faint, there are many bright stars 

 among them. Arcturus and Spica and 

 the star at A, Figure i, form a nearly 

 equal sided triangle, and this together 

 with the lines joining the star at A 

 and B is known as the Diamond of 

 Virgo. 



Even to the naked eye, Spica, Regu- 

 lus and the star at A are seen to be of 

 a much bluer color than Arcturus, 

 which is golden, while the star at D is 

 usually described as white. This last 

 is a most interesting object, having 

 what is described as a pale lilac com- 

 panion twenty seconds away which is 

 a beautiful object in a small telescope. 

 The constellation Leo is of great 

 antiquity, and indeed is prehistoric in 

 its origin. Some believe that the 

 Sphinx represents Virgo's head on 

 Leo's body to represent the passage 

 of the sun through these constellations 

 at the time of the rising of the Nile. 

 Pliny stated that the Egyptians wor- 

 shipped the stars of Leo because the 

 rise of the great river occurred when 

 the sun passed through this constella- 

 tion. The principal star of this beauti- 

 ful figure is Regulus, the Ruler, so call- 

 ed because for five thousand years it 

 was believed to rule the heavens. Four 

 thousand years ago its longitude was 

 measured in Babylonia, and twenty 

 centuries later Hipparchus, the Father 

 of Astronomy, from observations of 

 this star and of Spica made the wonder- 

 ful discovery of Precession of the Equi- 

 noxes. At the time of the first observa- 

 tion mentioned Regulus was almost 

 exactly at the summer solstice, so that 

 the sun passed before it at the time of 

 the longest day. Now the sun almost 



covers the star, which lies very close 

 to the ecliptic, on the 20th of August; 

 the change of date is owing to the slow 

 motion westward of the Autumnal 

 Equinox (at C, Figure 1) which is 

 known as the Precession of the Equi- 

 noxes. 



Regulus has a deep blue companion 

 about one hundred and seventy-seven 

 seconds away which is itself double, 

 while the stars at D, E and F are all 

 doubles also. The first is described as 

 the finest double star of the northern 

 skv, the brighter star being of a white 

 and the companion of a lilac color. 



Having thus studied the constella- 

 tion Leo, the observer may next turn 

 to a group of equally great antiquity, 

 the constellation Virgo, which though 

 not quite so high in the heavens is still 

 well above the ground in the southeast. 

 This constellation is filled with objects 

 of interest. The region between the 

 stars H. K, L and A is more crowded 

 with nebulus than any other region of 

 the heavens ; more than five hundred 

 have already been found in this little 

 space, many of which can be seen with 

 a small telescope. There are many in- 

 teresting double stars, of which that 

 at M is composed of two suns revolv- 

 ing about one another in the least cir- 

 cular of all orbits known in double star 

 systems, the time occupied by one 

 revolution being one hundred and 

 ninety years. 



***** 



The Planets in April. 



Mercury will attain its greatest dis- 

 tance east of the sun on April 7, and 

 this will be the most favorable time of 

 the present year to look for this little 

 planet. It will then be well north of 

 the west point of the horizon about 

 three-quarters of an hour after sunset, 

 when we will see the little world shin- 

 ing brightly in the twilight glow. The 

 planet in fact sets more than an hour 

 and one-half after the sun, but it is 

 more difficult to see as it approaches 

 the ground and therefore the observer 

 should begin to look for it as soon as 

 the greatest brightness of the twilight 

 glow has passed. On the evening of 

 April 1 1 the narrow crescent of the new 

 moon, by this time arrived east of the 

 sun, will draw very near to the planet, 

 though it unfortunately will not pass 



