The Milky Way 



they can apply the explanation which was 

 accepted in the case of Algol; for this it is 

 sufficient to imagine the two companions as 

 neighbouring flattened spheres, or ellipsoids of 

 revolution, turning in a plane which passes 

 through our eye. The apparent surface of such 

 a system will vary continuously, causing the 

 light emitted in our direction to vary in the 

 same sequence. Such is the theory applied by 

 Myers to a number of variable stars, and the 

 conclusions which he reaches are sufficiently 

 original to be worth mention. 



Let us take, as an example, the variable 

 star ft Lyrse to explain the periodical variation 

 of its brightness. It is sufficient to suppose 

 that it consists of two slightly flattened stars, 

 one bright and relatively small, the other 

 larger and less bright. These two masses would 

 revolve one around the other, almost touching, 

 and the mean density of the matter composing 

 them would be only half that of our atmospheric 

 air. According to this last datum (3 Lyrae 

 would not be a completely condensed system, 

 but would represent a nebula in course of 



transformation into a binary system, that is 



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