Vesta, Juno, Ceres, and Pallas. 295 



tronomical Society of London, who has given them in his As- 

 tronomical Tables and Formulce, a work which, with his 

 usual liberality, he has printed for the use of his scientific 

 friends. The planets are arranged in the order of their dis- 

 tance from the sun. 



Vesta. 



This planet was discovered by Dr Olbers on March 29, 

 1807. Its mean distance from the sun is 2,367,870 ; that of 

 the earth being considered as unity. 



It performs its sidereal revolution in 1325.7431 mean solar 

 days ; and its mean synodical revolution is 503,41 days. 



The mean longitude at mean noon at Greenwich, on Janu- 

 ary 1, 1820, was in 278° 30' 0" 4. 



Its mean motion in its orbit in a mean solar day is 16' 17", 

 9516. Its mean motion in 365 days, is consequently 99° 9' 

 15", 33. 



The longitude of its perihelion in Jan. 1, 1820, was in 249° 

 33' 24", 4. According to M. Santini, it has an apparent an- 

 nual motion of + 1' 34", 24. 



Its orbit is inclined to the plane of the ecliptic, in an angle 

 of 7° 8' 9", which, according to M. Santini, has an annual de- 

 crease of 0", 12. 



Its ascending node was, on January 1, 1820, in 103° 13 

 18", 2, which, according to M. Santini, has an apparent annual 

 motion of + 15", 63. 



The eccentricity of its orbit is 0.089,130; half the major 

 axis being considered as unity : subject to an annual increase, 

 according to M. Santini, of 0.000004009. 



The greatest equation of the centre is 10° 13' 22". 



Juno. 



This planet was first discovered by M. Harding on Sep- 

 tember 1, 1804. Its mean distance from the Sun is 2.669009, 

 that of the sun being considered as unity. 



It performs its sidereal revolution in 1592,6608 mean solar 

 days ; and its mean synodical revolution in 473,95 days. 



Its mean longitude at mean noon at Greenwich, on January 

 1, 1820, was in 200° 16' 19", 1. 



