INVESTIGATION OF THE ABEREATION IN 

 RIGHT ASCENSION AND DECLINATION*. 



THE following investigation of the formulas for Aberration 

 in Right Ascension and Declination will be found to be more 

 simple than that given in Maddy's Astronomy, p. 214. 



Let T L be the ecliptic, <r E the equator, P its pole, T a 

 point 90 behind the place of the Sun, S the place of the star ; 

 then 8 T will be the plane of aberration. 



Let or N= a, PN= 8, Sun's longitude = , and L T E= a>. 



1st. For the Aberration in Declination : produce SN to a 

 point Q, such that SQ = 90, and join TQ, TN. If A be the 

 coefficient of aberration, and AS the aberration in declination, 



AS = - A sin ST. cos TSQ = - A cos TQ, 

 as TSQ is a quadrantal triangle. 



* Cambridge Mathematical Journal, No. IX. Vol. II. p. 120, May, 1840. 



