ASTRONOMY WITH AN OPERA-GLASS. 



191 



powerful absorptive atmosphere, and which are believed on various 

 grounds to be, as Lockyer has said, " in the last visible stage of cool- 

 ing " ; in other words, almost extinct. This great, red star probably 

 in actual size exceeds our sun, and no one can help feeling the sublime 

 nature of those studies which give us reason to think that here we can 



Scorpio and Sagittarius. 



actually behold almost the expiring throes of a giant brother of our 

 giant Sun. Only, the lifetime of a sun is many millions of years, and 



its gradual extinction, even after it has reached a stage as advanced 

 as that of Antares is supposed to be, may occupy a longer time than 

 the whole duration of the human race. 



The opera-glass will show a number of faint stars scattered around 

 Antares. Turn now to Beta (/?) in Scorpio, with the glass. A very 

 pretty pair of stars will be seen hanging below /3. Sweeping down, 

 ward from this point to the horizon you will find many beautiful star- 

 fields. The star marked Nu (v) is a double which you will be able to 

 separate with a powerful field-glass, the distance between its com- 

 ponents being 40". 



And next let us look at a star-cluster. You will see on the map 

 an object marked 4 M., near Antares. Its designation means that it 

 is No. 4 in Messier's catalogue of nebulae. It is not a true nebula, but 

 a closely compacted cluster of stars. With the opera-glass, if you are 

 looking in a clear and moonless night, you will see it as a curious 

 nebulous speck. With a field-glass its real nature is more apparent, and 

 it is seen to blaze brighter toward the center. It is, in fact, one of 

 those universes within the universe where thousands of suns are asso- 

 ciated together by some unknown law of aggregation into assemblages 

 of whose splendor the slight view that we can get gives us but the 

 faintest conception. 



