184
The Evolution of the Stars [ch. vi
It now appears that the diagram we used to discuss the course of stellar
evolution in § 158 needs amendment. It was drawn on the supposition that
high surface-temperature was associated with high luminosity, and it now
appears that, except where fission enters into the problem, the exact reverse
is the case. To represent the configurations of simple stars, the lines OB, OQ,
etc., which represented stars at given surface-temperatures, must be replaced
by bands of finite width representing white dwarfs, K- ring stars, £-ring stars,
etc. And the white dwarf band must come lowest, in some position such as
OB in fig. 15, followed in succession by bands representing K- ring, X-ring
stars, etc.