( 481 ) 



increase in q is in agreement with sucli a supposition, but the 

 continual lengthening of the period seems to clash with it. 



15. Computation of the orbit from the spectrographs of 'Qm^ovoij^KY. 



In the computation of the orbit from the velocities in the line of 

 sight as derived by B. from the displacement of the bright i^-line 

 in the spectrographs of 1892, the method of Wilsing ^) has been 

 adopted. For very small excentricities it is to be preferred to that of 

 Lehman-Filhes. 



The first column contains the mean time of observation at Pulkowa; 

 the 2"<ï gives the phase in the light-period of 12.91 days. We have 

 assumed, in accordance with the formula of Argelander, as corrected 

 by Pannekoek, that the principal minimum occurred on 1892 Sept 25. 

 781 M. T. Greenwich (= 25^.865 M. T. Pulkowa). 



The 3'^ column contains the velocities, expressed in geographical 

 miles, reduced to the sun. They have been taken, with slight modi- 

 fications, from the Memorie della Soc. d. Spettr. It., vol. XXII. For 

 Belopolsky has applied a constant correction — 2.1 G.M. for the 

 velocity of the earth, whereas in reality this' velocity varies between 

 — 1.6 and —2.3 G.M. 



Phase 



Veloc 

 in G.M. 



0-C 



+0 05 

 —1.51 

 +1.82 

 —0.48 

 +0.20 

 —0.39 

 -0.89 

 +0.59 

 —0.19 

 —1.11 

 —0.46 

 +0.62 

 + 1.15 

 +0 42 



') Dr. J. Wilsing. Ueber die Bestimmuno; von Bahnelementen enger Doppelsterne 

 aus spectroskopischen Messungen der Geschwindigkeitscomponenlen. A. N. no. 3198. 



