18 



PREDICTION OF OCCULTATIONS. 



<c 



Log A 



Log .5 



o 



9.9971 



0.0000 



10 



9.9971 



0.0000 



20 



9-9973 



0.0002 



3° 



9-997S 



0.0004 



4° 



9-9977 



0.0006 



JO 



9.9979 



0.0009 



6o 



9.9982 



O.OOII 



7° 



9.9984 



0.0013 



rcos<?>' = i?cos<fi 



a = r cos <p' sin (H-t-d) 

 h = r cos (^' cos {ll-+-d) 



log A 

 u = a 

 V = rsin<p'cosi? — isiaD 



maiaM = p — u 

 mcQBM= q — V 



9-4192 



m' = Ik 



«/ = aAsinZ? 



«siniV = y — vl 

 ncosJV = q' — V 



log/t = 9-4354 



cos4' = 



» sin (Jf—iV) 

 k 



X ^ ^T,^ UTS ^sirnj/ 



t = cos(il!f— iV^)qF 



n n 



Upper signs for Immersion ; under signs for Emersion. 



tanP = 



Mean Solar Time of the Star's apparent contact with the moon's limb - 



= T+d+t 

 Angle from JVorth Point = Q 

 Angle from Vertex = V 



The angle 4' is to be taken out positive and less than 180°. If log?wsin(Jlf— i^ 

 be greater than log Jc, cos J/ will evidently be greater than 1, or impossible, and there 

 will be no occultation, except in some rare instances where the moon's limb passes 



