I 
/ 
CONTENTS 
int up to 
written in 
m earlier 
rch 1926; 
d be used 
branches 
together, 
srlapping 
book has 
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veet, but 
quantum 
electron, 
radiation 
electron 
is hoped, 
nation of 
Lot likely 
molecular 
a chance 
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physics, 
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acknow- 
heir care 
A. S. E. 
CHAP. 
PAGE 
T 
JL. 
Survey of the Problem . . . . 
1 
II. 
Thermodynamics of Radiation 
27 
III. 
Quantum Theory . . . . . 
44 
IV. 
Polytropic Gas Spheres . 
79 
V. 
Radiative Equilibrium . . . . 
. 
97 
VI. 
Solution of the Equations . . . . 
114 
VII. 
The Mass-Luminosity Relation 
145 
Vili. 
Variable Stars ...... 
. 
180 
IX. 
The Coefficient of Opacity . . . . 
. 
216 
X. 
Ionisation, Diffusion, Rotation 
. 
250 
XI. 
The Source of Stellar Energy 
289 
XII. 
The Outside of a Star . . . . 
321 
XIII. 
Diffuse Matter in Space . . . . 
371 
APP. 
I. 
Physical and Astronomical Constants . 
395 
II. 
References ....... 
. 
397 
Index 
DIAGRAMS 
403 
FIG. 
1. 
Distribution of Temperature and of Mass in 
a Star 
86 
2. 
The Mass-Luminosity Curve compared with Observations 
153 
3. 
Statistics of Absolute Magnitude and Spectral Type . 
175 
4. 
Schematic Type-Magnitude Diagram . 
176 
5. 
Spectral Energy Curve of the Sun 
328