[ 290 ] 

 L 1 1 . Proceedings of Learned Sociei ies. 



ROYAL ASTRONOMICAL SOCIETY. 



AGREEABLY to the intention expressed in our last Number, we 

 now give abstracts of two of the most important communications 

 read on June 14th. 



Notice of the Elliptic Orbit of £ Bootis, with a further Approxima- 

 tion to the Orbit of y Virginis. By Sir John Herschel. 



The elements of the orbit of £ Bcbtis are given for the first time ; 

 those of y Virginis are recalculated by the aid of observations made 

 in the current year, by Sir J. Herschel and others, which differ 

 materially from the Ephemeris published in the Supplement to the 

 Nautical Almanac for 1832. Comparisons of the calculated results, 

 with observations, are given in both cases. 



The elements are as follow : — 



t, Bootis. 



Semiaxis major a = 12"*56 



Excentricity e = -59374 



Pos. of perihelion p = 138° 24' 



Angle between lines ) 



of nodes and ap- > A = 100° 59' 



sides S 



Inclination to the \ Qft0 K . 



plane of the sky | y ~ bU 5 

 Position of node ... &= 359° 59' 

 Period in tropical! p _ ,,*,, 



years J 



Mean motion n = — 3°*0733 



Perihelion passage, Dec. 17, 1779. 



" These elements are interesting in several respects. In the first 

 place, the period they indicate fills up an intermediate and wanting 

 link between the short periods of n Corona, £ Ursa:, &c, and the 

 much longer ones of Castor, a Corona, 61 Cygni, y Virginis, &c. 

 establishing (so far as we can at present rely on such determina- 

 tions,) a connected scale of periods, from less than half a century 

 to upwards of six centuries. The great amount of the excentricity 

 of the orbit in question strengthens the induction which already 

 begins to assign, in no unequivocal manner, orbits rather of a co- 

 metary than a planetary character to the binary stars generally. 

 This orbit, moreover, is the most oblique to the line of sight which 

 has yet been calculated ; and as the apparent position of the pro- 

 jected perihelion is not very far from making a right angle with 

 the line of nodes, the longer axis of the real ellipse is violently 

 fore shortened, and the whole character of the apparent ellipse 

 completely distorted, as seen in projection, from what it is in 

 reality." 



y Virginis. 



Major semiaxis a = 12" # 090 



Excentricity e = 0'8335 



Perihelion projected zs = 36° 40' 



Perihelion from node on the orbit > = 282° 21' 



Inclination to heavens y= 67° 2' 



Node ft = 97 23 



Period in tropical years P = 628*90 



Mean annual motion n = — 0°«57242 



Perihelion passage t = 1834-63 



