Discovery of two new variable Stars 95 



supplied by the Berlin Academical Charts, the southern 

 halves of which fall entirely within their limits. 



N. R. Pooson. 



Madras Observatory, ) 

 December 1863. j 



On the discovery of Two new variable Stars, by N. R. 

 Pogson, Esq., f. r. a. s., Government Astronomer. 



r JPHE search for new minor planets maintained during the 

 past year with the Madras equatoreal, although not 

 successful in its primary object, has nevertheless been the 

 means of adding to the list of recognised variable stars, two 

 interesting members hitherto unknown. Trusting that a 

 brief account of these discoveries will not be out of place in 

 the Madras Journal, the following particulars have been 

 communicated. 



The first, now known as XJ Scorpii, was detected on the 

 ^ 20th of May 1863, shining as a star of the ninth magnitude, 

 in a spot in which no such object had been previously 

 recorded, though most carefully watched in each successive 

 May since 1854. Micrometrical measurements from an ad- 

 jacent known star at once proved its fixity, and thereby 

 suggested its probable variability. The following evening 

 sufficed not only to confirm this impression, but also to 

 show that the new variable was one of an extraordinary 

 character, changing in brilliancy with a rapidity equalled 

 only by one star of a similar nature, discovered by Mr. Hind, 

 in the constellation Gemini, in December 1855. Eight 

 days later, when last seen, U Scorpii had diminished to 

 below the 12th magnitude, or less than one -seventeenth of its 



