POPULAR ASTR< >\< >MY 



203 



the phenomena most generally blamed 

 for changes in the weather — but as yet 

 without scientific success. To explain 

 storms by the sun's crossing an 

 imaginary line is a still farther cry. 

 Autumn begins on September 23, 5.3] 

 P. M., Eastern Standard time. 



CONSTELLATIONS. 



The star which is found almost over- 

 head in the early part of the evening is 

 the first magnitude star Vega, the chief 



stars of this constellation show interest- 

 ing results. The second star known as 

 Beta Lyra has a most unusual spectrum 

 consisting of dark and light lines which 

 change and alter in a mysterious fashion. 

 The dark lines of any spectrum are 

 caused by absorption of light by the star's 

 atmosphere, while bright lines show the 

 presence of a gas-giving light of its own. 

 In addition, this star has a light which 

 varies in amount, being brighter at one 

 time than another. Anvone who watches 



Evening SkyMap for September 



3EPT MOON PHASES 

 NEW MOON, Sept.5. 

 FIRST Qtr.Sept II 

 Full moon, Sept i&. 

 LAST Qjr .Sept 25 



NORTH 



Columbia 

 Unive^- 



MAP 



for 

 9PM15T 



8PH15") 

 7PM30* 



FACE SOUTH AND 

 HOLD THE MAP OVER 

 YOUR HEAD-THE TOP 

 NORTH. AND YOU WILL SEE 

 THE STARS ANDPLANETS 

 JUST AS THEY APPEAR 

 IN THE HEAVENS 



SOUTH 



The Arrow Through 



THE TWO STARS IN THE; 



BOWL OF THE BIG DIPPER 



POINTS TO THE NORTH STAR. 



THE 5TAR AT THE END OF THE 



HANDLE OFTHE LITTLE! DIPPER. 



one in the constellation of the Lyra. At 

 New York City, this star comes within 

 two degrees of the zenith. This distant 

 sun, many times more brilliant than the 

 centre of our system, has not progressed 

 so far in the scale of development as 0111 

 sun, as shown by its bluish white color. 

 The spectroscope shows it to be of the 

 "first type," and informs us that its at- 

 mosphere consists mainly of hydrogen 

 gas. The spectroscope applied to other 



the star closely with the naked eye can 

 detect a change, for the range is over 

 one magnitude, from 3.4 to 4.5. The 

 period of this change is 12.9 days. Beta 

 is a trifle more than six degrees south- 

 east of Vega. Still farther to the south- 

 east is Gamma Lyra, a fine star with 

 which to compare Beta. At times Beta 

 is brighter than Gamma, at times fainter. 

 The writer has discovered Gamma Lyrae 

 to be a "spectroscopic binary," or a star 



