.18 PARALLAXES OF STARS— BOOTH AND SCHLESINGER. 



(490) ^ Serpentis, 15 h 39 m , + 2° 50'. 



[Memoirs National 

 [Vol. XIX, 



+13.60 c+ 12.55/1+ 1.16 ir= + 



+137.49 +18.93 =- 



+ 8.34 =+ 



Probable error for unit weight, ± 



Anntial proper motion in R. A., — 



Relative parallax, + 



.0491 mm. c=+0.0043 mm. 



.0290 ,i=- .00101. 



.0107 r=+ .00298. 



.0014 mm. = ±".020. 

 '.054 ±".008. 

 '.043 ±".008. 



No other determination of this parallax has been published. Boss gives — 0".082 for the 

 proper motion. 

 (49t) 2 2052, 16 h 24 m , +18° 37'. 



+12.20 c+ 9.02/j+0.87tt=+ 0.1065 mm. c=+0.0128mm. 

 +59.31 +2.38 =- .2251 m=- .00589. 



+8.35 =+ .0258 tt=+ .00343. 



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

 Annual proper motion in R. A., — ".314 ±".013. 

 Relative parallax, + ".050±".008. 



Other determinations of this parallax are: At Mount Wilson (spectroscopic), +0".05S; 

 Yale (heliometer), +0".082±0".030. Porter gives -0".327 for the proper motion. 



This is a binary with slow but unmistakable orbital motion. The components are of the 

 same magnitude and are now close. The measures refer to their combined image. 



