32 



PARALLAXES OF STARS— BOOTH AND SCHLESINGER. 



[Memoirs National 

 [Vol. XIX, 



BRIGHTER COMPONENT. 



+12.50 c+ 7.72 M - 2.08 tt= + 0.0133 mm. c= +0.0005 mm. 

 +163.38 +10.73 =+ .2777 m=+ .00152. 



+ 6.96 =+ .0315 *-=+ .00233. 



Probable error for unit weight, ± .0017 mm. =±".025. 

 Annual proper motion in R. A., + ".081 ±".008. 

 Relative parallax, + ".034±".010. 



FAINTER COMPONENT. 



+11.20 c+ 10.23ji -1.93 tt=+ 0.0097 mm. c=-0.0003mm. 

 +127.21 +£.92 =+ .2262 M =+ .00170. 



+6.28 =+ .0245 t=+ .00220. 



Probable error for unit weight, ± .0014 mm. = ±".021. 

 Annual proper motion in R. A., + ".091±".007. 

 Relative parallax, + ".032±".009. 



The mean is +0". 033 + 0". 007. No other determination has been published. 



An examination of all the catalogues in which the positions of these two stars are given 

 yields +0".093 and +0".074 for the two components in right ascension, and +0".05 and 

 + 0".05 for those in declination. That the two proper motions are the same is shown by the 

 micrometer measures. Therefore these two stars, 42" apart, are physically related. Accepting 

 + 0".036 as the absolute parallax of the pair, the projection of their linear separation on the 

 celestial sphere exceeds more than a thousandfold the distance between the earth and the sun. 



The preceding star is itself a very close double, ,J 1092, in rapid orbital motion. 



(520) 



OS 478, 22 h 40 m , +38° 56'. 



+13.30 c+ 19.41 /j-2.31 sr=- 



+100.97 -2.91 =- 



+7.91 = + 



Probable error for unit weight, ± 



Annual proper motion in R. A., — 



Relative parallax, + 



0.0422 mm. c= -0.0028 mm. 



.0793 n = - .00025. 



.0087 tt=+ .00020. 



.0012 mm. = ±".018. 

 '.013 ±".008. 

 '.003 ±".006. 



Other determinations are: Mount Wilson (spectroscopic), +0".005; Mount Wilson (trigo- 

 nometric), + 0".002 ±0".008. Boss gives -0".004 for the proper motion. 



The companion is two magnitudes fainter and is distant 3". The two have the same 

 small proper motion. There is a third star of the twelfth magnitude distant 11", which forms 

 /3450. It is not yet known whether this is physically related to the two others. 



