ASTRONOMY 



Virgin, and Regulus, at the end of the handle 

 of the Sickle, in the Lion. 



The Heavens in Summer. In the second of 

 the maps will be noticed several new constel- 

 lations. In spring they could have been seen 

 only after midnight. Cassiopeia, in the north- 

 east, is easily recognized by its resemblance to 

 the letter Af. Scorpio, the Scorpion, in the 

 south, is another constellation not difficult to 

 find. Its brightest star, Antares, is red in color. 

 Near the eastern horizon is Altair, a star which 

 gives ten times as much light as our sun. It 

 is only fifteen light years away from us, and 

 i> traveling in this direction about twenty- 

 seven miles in one second, and after 100,000 

 years will occupy the same place in the uni- 

 verse that our solar system does now. But 

 by that time we shall be millions of millions 

 of miles away. 



The Heavens in Autumn. At this time of 

 the year the star of the south is Fomalhaut, 

 which may be recognized as the first magnitude 

 star at the end of the wavy line which repre- 

 sents the water flowing from the jar of 

 Aquarius, the Water Carrier. The constellation 

 Andromeda, toward the east, contains one of 

 the two nebulae which may be seen without a 

 telescope. This nebula is just north of the 

 second magnitude star which marks Andro- 

 meda's waist ; its length is supposed to be three 

 million million (3,000,000,000,000) miles, and it 

 is like a huge pinwheel in the skies. The star 

 which marks the foot on which Andromeda 

 stands is proved by the telescope to be three 

 stars, one orange, one green, one blue. Algol, 

 on the eastern horizon in Perseus, was known in 

 olden times as the Demon, or the Winking 

 Star. Ordinarily it is of the second magnitude, 

 but for eighteen minutes on every third day 

 it sinks one degree in magnitude. The won- 

 derful spectroscope has proved to us that this 

 variation is caused by a dark companion star 

 which passes in front of it. 



The Heavens in Winter. No other constella- 

 tion contains so many bright stars as Orion, 

 the Warrior, seen in the south in winter time. 

 Two of them are of the first magnitude, Betel- 

 geux, whose dull orange-red shows it to be 

 a sun whose brilliancy is declining, and Rigel, 

 seventh in brightness among all the stars. In 

 the sword of Orion may be seen the nebula 

 mentioned above. Sirius, the Dog Star, is by 

 far the greatest light-giver of all in the heavens, 

 and may be seen both north and south of the 

 equator. Procyon, the Little Dog Star, is next 

 to Rigel in brightness. Aldebaran, a rosy star 



446 ASTRONOMY 



which forms the flaming eye of the Bull, is one 

 of those which is moving farther away from us. 

 It is directly in the path of the moon, by which 

 it is often hidden. Its companion star may 

 be seen with a telescope. The Pleiades, at the 

 back of the Bull's neck, are a group of tiny 

 twinklers of which from six to eleven may be 

 seen by the naked eye, though there are ac- 

 tually about 3,000. Photography shows them 

 to be wrapped in a nebulous cloud, and they 

 are thought to be closely related stars which 

 are developing from it. In spite of their faint- 

 ness many of them are a number of times 

 brighter than our sun, and separated from each 

 other by several light years. In ancient times 

 the Pleiades were supposed to be Atlas, his 

 seven daughters and their mother, and there 

 is a legend of a lost Pleiad. Castor and Pollux, 

 the Twins, are of interest because a few hun- 

 dred years ago Castor was the more brilliant, 

 but is now less bright than Pollux. This is 

 because the latter is approaching us, the former 

 moving away. Castor is a green star. 



Conspicuous in the sky at all seasons is the 

 broad luminous band known as the Milky Way 

 or Galaxy. To us it seems but a softly-lighted 

 cloud, but to the astronomer with a very pow- 

 erful telescope it shows itself as a multitude of 

 stars, so far away that it takes the light from 

 them three thousand years to reach the sun. 

 See MILKY WAY. 



The Planets. Of those worlds which, like 

 our own, move about our sun, Venus, Jupiter 

 and Mars are most familiar to us. Venus was 

 Hesperus, the evening star of the ancients, and 

 Lucifer, the morning star as well, for people 

 did not know the two were the same. Jupiter, 

 whose moons give it an imperfect appearance, 

 is nearly as bright as Venus, and Mars may be 

 distinguished by its redness. All these "wan- 

 derers" appear at different times in different 

 months, because their periods of revolution 

 about the sun do not correspond to our own. 

 Saturn is a bright; slightly red star. Uranus 

 may seldom be seen without a telescope, and 

 Neptune is never visible to the naked eye. 

 Mercury is difficult to see because of its near- 

 ness to the sun. C.H.H. 



Consult Hawk's Boy's Book of Astronomy; 

 Newcomb's The Stars; Martin's Friendly Stars. 



Related Subjects. To the reader interested 

 in astronomy the following list of articles on that 

 subject contained in these volumes will be most 

 helpful : 



GENERAL 



Apogee Ascension and 



Apsides Pectination of Stars 



