108 



RECORD OF SCIENCE FOR 1886. 



Professor Holden, while at tlie Washburn Observatory, compiled a 

 list of all published corrections to his star catalogues, inserting the 

 errata in the bodies of the books themselves. The original sources from 

 which the errata were copied are given in the fourth volume of the 

 Publications of the observatory. The value of this list will be appre- 

 ciated by all astronomers who have occasion to make use of star cata- 

 logues. 



The catalogue of stars of the British Association has been advertised 

 recently at 170 mark, or about $43. • 



STELLAR PARALLAX. 



Prof. A. Hall has given in Appendix ii to the Washington Observa- 

 tions for 1883 the results of recent observations made with the 26 inch 

 equatorial to determine the parallaxes of a Lyrre, 61 Cygni, 40 (f/) 

 Eridani, and 6 ,3 Cygni. The results are as follows: 



Date. 



February 23, 1883, to March 4, 1884.. 



July 31, 1883, to April 15,1886 



May 24, 1880, to July 2, 1881 



October 24, 1880, to January 26, 1886. 



40 (o2) Eridani 



6 B Cygni 



a Lyrm 



61 Cygni 



Parallax. 



No. of 

 observa- 

 tions. 



+ 0. 223 i 0.0202 

 — 0. 021 -j- 0077 

 -f 0. 134-1-0.0055 

 + 0. 270 i 0.0101 



30 



54 



128 



101 



Dr. W. Schur has published in the Astronomische iSrnchrichteii (vol. 

 114, p. 161), a discussion of the parallax of the double star //:^ Auriga3 

 from measures of position, angle, and distance made with 6-incli Strass- 

 burg refractor, in 1883-'85. The final value for the parallax of the 

 fainter (ninth magnitude) star is + O'Mll ± 0" 034. " Herr Schur 

 thinks that he is justified in asserting that the parallax of this star is 

 at least CM — a remarkable result, considering the fixity of the object." 



40 (o^) Eridani. — Mr. J. E. Gore, using Professor Hall's parallax, 

 0".223, has obtained by means of elements which he has computed, the 

 following figures : 



Distance of 40 Eridani from the earth 924,955 



Mean distance between the components, B C 26. 86 



Sum of masses B C i 



Suu's mass =:1 \ - ^* ""■' 



Tlie unit of distance is the mean distance of the earth from the sun. 



DOUBLE STARS. 



Two recent papers on personal equation in double-star observatio'us 

 will be found of especial interest to those engaged in this class of work. 

 The first paper forms the subject of a thesis by M. Bigourdan, of the 

 Paris Observatory, submitted for the degree of doctor of physical 



