Notes to Catalogue of Zodiacal Stars. 57 



Br. and Pi. is in R.A. -0"-22, in Decl. ~0"-05. A very 

 remarkable double star. According to Piazzi the pre- 

 ceding star is 3*4 mag., the following 3 mag., difF. R.A. 

 5"*8 determined with the utmost care: diff. Decl. 0""0. 

 In a note he remarks, that Dr. Hornsby first determined 

 the distance of the stars in R.A. =3"*8, which measure 

 remained constant for 20 years. Castor is the first of Sir 

 W. Herschel's 2nd class of double stars, and in his ori- 

 ginal catalogue (Phil. Tr. 1782) he sets down the distance 

 5"'156 diameters included. Pos. 32°*8 n. prec. In the 

 volumes for 1803 and 1804, this indefatigable observer 

 stated the results deduced from a series of observations 

 from 1783 to 1803, viz. — that the two stars revolved 

 round their common centre of gravity in 3 4'2 years ; in a 

 plane nearly perpendicular to the visual line. This dis- 

 covery, which appears to have been wholly unknown to 

 Piazzi, will account for the discoi'dance between his mea- 

 surement and that of Hornsby. 



B. 162 Geminorum.) This is the star, situate between 68 and 

 61 Gem. noticed by Hers. (Phil. Tr. 1783) as among the 

 considerable stars not comprised in any existing catalogue. 



B. 168 Geminorum.) Position from Bradley. 



M. 303, 304.) The synonyms are wanting in Piazzi. 



75 a- Gemuiorum.) Pr. mot. R.A. +0''-06. Decl. — 0"-21. 



76 c .) Erroneously called L in Piazzi. 



78 /3 .) Called Pol/iLr. The R.A. in the text is 



that given by Bouvard. (Coim. d. T. 1 821.) Thatof Piazzi 

 is — 0''*3. Both authorities agree in the Declination. The 

 pi'oper motions are as follow : 



R.A. Decl. Great Circle. 



As given by Bouvard — 0"'647 +0"-080 



From Br. and Piazzi — 0"'742 — 0''058 0"-655 



Piazzi's own comparison —0''*72 — 0"*11 



Amultii)lestar. Hers. VI. 42. " Extremely unequal. The 

 nearest distance 1 1G""75, rather full measure. Pos. 24°'5 

 n. foil, not extremely accurate. This is the smallest. The 

 next distance 197"'3 pretty accurate. Pos. 15°-93 n. fol- 

 lowing." The same observer, in Jan. 1796, records thus, 

 " /3 Gem. appears to be of a deeper colour than it was a 

 good many jears ago. I should now place it among the 

 red or ruddy stars, which tbrmerly I did not use to do." 



Page 50. 



Ano7i. R. A. 1 1 3° 52'.) Froni Lai. H. C. 53. Double. Hers. 

 II. 65. " Full ^1° n. foil. /3 Gem. in a line i'rom 8 con- 

 tinued through it; the star next to the middle one of 

 three, nearly in a line. Excessively unequal ; L. r. w. S. d. 



Vol. 62. No. 303. Julij 1823. H With 



