48] 



ON THE MEAN PLACES OF 84 FUNDAMENTAL STARS. 



399 



BESSEL'S FICTITIOUS YEAR. 



The value of the precession given by Dr Peters refers to the tropical 

 year as the unit of time, and the places of the Stars given by him and 

 all the other German Astronomers correspond to the beginning of Bessel's 

 fictitious year, viz. to the instant when the Mean Longitude of the Sun 

 = 280. It seems desirable for the sake of uniformity to adopt the same 

 usage, and therefore the places of the Stars found from Airy will require a 

 small correction. 



The Epochs to which the Greenwich Catalogues of 1840 and 1845 

 most nearly correspond follow the beginnings of the several fictitious years 

 by O d '580 and O d -627, that is by O y> 001588 and O y '001716, respectively. 



Hence we have 



y. 

 Correction to the Greenwich Place for 1840= -0'001588 x (Ann. Var. for 1840) 



1845= -0-001716 x (Ann. Var. for 1845). 



LE VERRIER'S CORRECTIONS OF THE RIGHT ASCENSIONS OF MASKELYNE'S 

 35 FUNDAMENTAL STARS FOR 1755. 



Mr Farley's preliminary calculations were completed when Le Verrier 

 published in the Comptes Rendus the corrections which a new and more 

 complete reduction of Bradley 's observations of these Stars shewed to be 

 required to be applied to the Right Ascensions for 1755 as given in the 

 Tabulae Regiomontance. 



