PLEASURES OF THE TELESCOPE. 473 



apertures in order to determine for ourselves what the colors of 

 the components are. There is considerable diversity of opinion 

 on this point. Some say the larger star is pale red and the smaller 

 light blue; others consider the color of the larger star to be 

 greenish, and some have even called it white. The magnitudes 

 are five and nine, distance 6", p. 350. 



Auriga contains several noteworthy clusters which will be 

 found on the map. The most beautiful of these is 1295, in which 

 about five hundred stars have been counted. 



The position of the new star of r893, known as Nova Aurigae, 

 is also indicated on the map. While this never made a brilliant 

 appearance, it has given rise to a greater variety of speculative 

 theories than any previous phenomenon of the kind. Although 

 not recognized until January 24, 1892, this star, as photographic 

 records prove, made its appearance about December 9, 1891. At 

 its brightest it barely exceeded magnitude four and a half, and 

 its maximum occurred within ten days after its first appearance. 

 When discovered it was of the fifth magnitude. It was last seen 

 in its original form with the Lick telescope on April 26th, when 

 it had sunk to the lowest limit of visibility. To everybody's 

 astonishment it reappeared in the following August, and on the 

 17th of that month was seen shining with the light of a tenth- 

 magnitude star, hut presenting the spectruTU of a nebula ! Its 

 visual appearance in the great telescope was now also that of a 

 planetary nebula. Its spectrum during the first period of its visi- 

 bility had been carefully studied, so that the means existed for 

 making a spectroscopic comparison of the phenomenon in its two 

 phases. During the first period, when only a stellar spectrum 

 was noticed, remarkable shiftings of the spectral lines occurred, 

 indicating that two and perhaps three bodies were concerned in 

 the production of the light of the new star, one of which was 

 approaching the earth, while the other or the others receded, 

 with velocities of several hundred miles per second ! On the 

 revival in the form of a planetary nebula, while the character of 

 the spectrum had entirely changed, evidences of rapid motion in 

 the line of sight remained. The nebulous speck which represents 

 all that is left of Nova Auriga? has not yet (February, 1895) faded 

 from sight. 



But what was the meaning of all this ? Evidently a catas- 

 trophe of some kind had occurred out there in space. The idea 

 of a collision involving the transformation of the energy of mo- 

 tion into that of light and heat suggests itself at once. But what 

 were the circumstances of the collision ? Did an extinguished 

 sun, flying blindly through space, plunge into a vast cloud of 

 meteoritic particles, and, under the lashing impact of so many 

 myriads of missiles, break into superficial incandescence, while 



