NEW STAR IN THE CONSTELLATION SWAN. 63 



tion was it that suddenly produced the incandescence of the sun of 

 the Corona, transforming it from a star of the ninth to one of the 

 second magnitude ? 



What would become of our planet were such a revolution as this 

 to take place in the sun, and were the calorific and luminous radiation 

 to be suddenly increased a hundred-fold? 



saiiiii 



Fia. 2. Spectrum of the New Stab in the Constellation op the Swan. (From Cornu.) 



But let us come to the new star of the Swan, which is the main 

 object of this article. Here is a very brief narrative of its discovery. 



Julius Schmidt, director of the observatory at Athens, recently 

 wrote to M. Le Verrier the following letter : 



" On November 11th, at S* 40" in the evening, I saw a star of the third 

 magnitude in the zenith, near p Cygni. Observations with the refractor of 

 the observatory, at Q"* SO", gave the position of the star as follows : 



18Y6. Right ascension 21'' 36 50.4' 



North declination 42 16' 30.5" 



*' The position for the year 1855 would be : 



Right ascension 21^ 36" 1.2' 



Declination 42 11' 1" 



" It does not occur in the Bonn " Durchmusterung des Himmels." The 

 star is strongly yellow in color. At midnight it was more intense than ji Pegasi 

 (which is set down as of the third magnitude in Heis's catalogue). On Novem- 

 ber 20th the star was not visible. On the 21st, 22d, and 23d, the sky at Athens 

 was overcast. From November 24th out, it has steadily declined in brightness, 

 and on December 8th the star was a little below the sixth magnitude." 



At Paris, too, the sky was almost constantly overcast for some 

 days after the reception of Schmidt's letter. By taking advantage 

 of infrequent and imperfect seasons of clear sky. Prosper Henry suc- 

 ceeded in observing the new star. Compared with the star 915 of 

 Weisse's catalogue (hour 21), it had this approximate position: 



1876. O Right ascension 21" 36" 50' 



Declination -H 42 16' 34" 



It was of the fifth magnitude, and appeared to be of a greenish 

 color, almost blue, as compared with a neighboring star (42,304 of 

 Lalande). 



The new star was also observed at Vienna by Littrow. To him 



