258 Mr. J. N. Lockyer. On the Classification [Jan. 10, 



Table III continued. 



VII. Binary Stars, Class 4. Very Unequal Magnitudes, the smaller 

 Star being Slue. 



The next class to be considered is that in which the companion is 

 of relatively small magnitude, and is blue, green, or grey, the primary 

 usually being white or yellow. 



A binary star of this class can be equally well explained by starting 

 the two carves at the same point, or starting one later than the other. 

 In the former case we should have to regard the one with the smaller 

 magnitude as having the greater mass, and the two curves would be 

 as in fig. 24, a. If we take the one with the smaller magnitude as 

 having the smaller mass we shall have the curves as in fig. 24, b. 



3TiG. 24. Light curves of the components of a binary star of Class 4. a represents 

 the case on the assumption that both components condensed from a double 

 nebula, whilst b represents the case on the assumption that the companion is a 

 cometary addition. 



It seems probable, therefore, that we shall never be able to tell 

 whether the components of a binary star of this class have both con- 



