Academy of Sciences.] 

 No. 2.] 



(492) and (493) 



INDIVIDUAL DETERMINATIONS. 

 u Draconis, 17 h 3 m , +54° 36'. 



19 



BRIGHTER COMPONENT. 



c= +0.0004 mm. 

 M=- .00213. 

 t=+ .00201. 

 = ±".030. 



+10.40 c+ 0.35/i-1.78tt=- 0.0001mm. 



+78.77 +4.14 =- .1597 



+6.05 =+ .0026 



Probable error for unit weight, ± .0020 mm. 



Annual proper motion in R. A., — ".114±".012. 



Relative parallax, + ".029 ±".013. 



FAINTER COMPONENT. 



+ 10.40 c+ 0.35 m-1.78 ir=+ 0.0086 mm. o=+0.0015 mm. 

 +78.77 +4.14 =- .1537 n=- .00214. 



+G.05 =+ .0091 tt=+ .00340. 



Probable error for unit weight, ± .0020 mm. = ±".030. 

 Annual proper motion in R. A., — ".114±".012. 

 Relative parallax, + ".050±".013. 



The mean is +0".039±0".009. 



Other determinations are: Yerkes +0".039±0".008 and +0".049±0".009; Mount Wilson 

 (spectroscopic), +0".026 and +0".028. Boss gives -0".068 for the proper motion of the 

 midway point. 



There is a thirteenth magnitude star distant 12" which has no physical relation to the 

 two others. 



