INDEX
407
Spectral type, 2; Saha’s theory of, 345;
temperature scale, 141; magnitude sta
tistics, 175; progression in Cepheids, 181,
208; range, 186; comparison of giants and
dwarfs, 361
Stability of a star, 142, 303
Stark effect, 353, 355
Stationary calcium lines, 377
Stebbins, J., 209
Stefan’s law, 38
Stewart, J. Q., 354
Stimulated emission, 50, 303, 365
Strömberg, G., 207
Subatomic energy, 292
Subordinate lines, 343, 346
Sun, 149; astronomical constants for, 395;
darkening at the limb, 324, 328; spectral
energy curve, 328; photosphere, 336, 360;
height of chromosphere, 362, 367
Superelastic collisions, 339, 373
Superperfect gas, 267
Surface-brightness and effective tempera
ture (table), 139
Switches of orbits, 229, 375
Target for electron capture, 221, 245
Temperature, inside a star, 14, 84, 120, 136;
mean temperature, 88, 94 ; in outer layers,
323 ; second approximation, 332 ; in inter
stellar space, 371, 377. See also Central
temperature, Effective temperature
Temperature-gradient in Capella, 15
Tensors, 57, 69
Thermal diffusion, 276
Thermodynamical equilibrium, 44, 47; ap
plication to outside of a star, 323, 338
Thermometric temperature, 32
Thomson, J. J., 294
Thunderstorms, stellar, 344
Time, direction of progress, 44
Time-scale, 290, 293, 309 .
Transmutation of hydrogen, 292, 296, 314
Valency electrons, 72, 379
Valve of heat engine, 200, 202
Van der Waals’ equation, 131, 167, 259, 262
Variable stars, Cepheid, 157, 180, 290;
eclipsing, 156, 208; long period, 206
Velocity curves of Cepheids, 180, 205
Virial, 260
Viscosity, 280
Vogt, H., 285, 311
Volts, conversion to ergs and Angstroms,
396
Wave-length of maximum energy, 140, 325;
of energy levels, 252; of subatomic emis
sion, 316; changed by scattering, 76; con
version to volts, 396
Weights of atomic states, 49, 61, 67, 230; for
calculating opacity, 112
White dwarfs, 170, 306
Width of absorption lines, 353, 367
Wien’s law, 39, 48
Wilson, C. T. R., 301, 320
Woltjer, J., 203, 238, 240
X-rays, 21; spectra, 70, 230, 234; absorption
coefficients, 22, 217, 236
von Zeipel, H., 162, 282, 287
Zonal harmonics, 105
CAMBRIDGE: PRINTED BY W. LEWIS, M.A., AT THE UNIVERSITY PRESS
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