- α Aquilæ, see Altair
- α Canis Majoris, see Sirius
- α Canis Minoris, see Procyon
- α Centauri, distance, 33, 35
- luminosity and weight, 48
- system of, 40, 263, 279, 280
- α Herculis, 259, 272
- α Lyrae, 33
- α Orionis, see Betelgeux
- α-particles, 112, 116, 117, 118
- and Plate XIII (p. 113)
- α-rays, 111
- α Scorpii, see Antares
- Absolute temperature, 102
- Absorption lines and spectrum, 51, 126
- Actino-uranium, 154, 155
- Adams, J. C., 18, 19
- Adams, W. S., 62, 343
- Age of earth, 14, 151 ff., 248
- of stars, 155 ff.
- of sun, 180, 184
- of universe, 336
- Aitken, R. G., 171, 188
- Altair (α Aquilæ), 33, 278
- Andromeda, Great Nebula M 31 in, Plate IV (p. 30),
- 30, 70, 71, 72, 204, 206, 208, 215, 335
- age, 335
- distance, 71
- rotation, 206
- size, 30
- weight, 71, 208, 215
- Andromedid meteors, 251
- Angstrom unit, defined, 256
- Angular momentum, conservation of, 205, 217, 232
- of solar system, 232
- Annihilation of matter, 185, 191, 193, 298, 331
- Antares (α Scorpii), 259, 272, 273, 278
- internal constitution of, 273, 291
- Aquarid meteors, 251
- Aristarchus of Samos, 2, 13
- Aristotle, 2, 5
- Arrangement of solar system, 16, 240 ff.
- Bode’s law, 19, 20
- Copernican, 3, 5, 6, 27, 32
- Ptolemaic, 2, 4, 6, 8, 31
- Asteroids, 17, 226, 240, 247, 252, 348
- Ceres, 17
- distance of, 19, 20, 252
- Eros, 34
- origin of, 247, 252
- Aston, F. W., 119, 154, 185
- Atmosphere, of earth, 195, 343
- of moon, 196
- of planets, 196, 343, 344, 348
- of sun, 195
- Atomic nuclei, 108, 117
- disintegration of, 111, 117
- size and weight of, 109
- structure of, 119, 139, 147
- Atomic numbers and weights, 110, 287
- in stellar matter, 306, 311
- Atomic theory, 92, 103
- Atoms, 103, 318
- structure of, 106
- synthesis of, 148, 149, 185
- Availability of Energy, 326, 329
- β Aurigae, 54, 58
- β-particles, 112, 113, 116, 145 and Plate XIII (p. 113)
- β-rays, 111, 145
- B.D. 6° 1309, see Plaskett’s star
- Bacon, Roger, 1
- Becquerel, H., 110
- Bentley, R., 197
- Berenice’s hair, 39
- Bessel, F. W., 33
- Betelgeux (α Orionis), 259, 272, 278
- Bickerton, A. W., 235
- Biela’s comet, 251
- Binary systems, 39, 40, 52, 54
- birth of, 217
- eclipsing, 54, 58
- loss of weight in, 188, 228
- orbits of, 46, 47, 167
- origins of, 169, 219, 297
- relative weights of components in, 188
- subdivision in, 228
- weights of, 48, 55
- Birth of binary systems, 217
- of nebulae, 204
- of planets, 232, 237
- of satellites, 232, 241
- of stars, 209
- Blackett. P. M. S., 117, 118
- Blue stars, 62
- Bode’s law, 19, 20, 252
- Bohr, Niels, 124, 128, 129, 131, 304, 305
- Bowen, J. S., 143
- Boys, C. V., 44
- Brownian movements, 159, 163
- Bruno, Giordano, 3, 4, 344
- Buffon, G. L. L., 235
- Bumstead, H. A., 113
- Burton, E. F., 143
- γ-rays, 111, 114, 122, 139, 144, 145
- Cameron, G. H., 143
- Campbell, W. W., 321
- Candle-power of stars, 49, 55, 179, 188;
- see Luminosity
- Capella, 278
- Cassini, D., 23
- Cavity-radiation, 123, 255
- Cepheid variables, 55, 56, 57, 59, 60, 70, 209
- mechanism of, 223
- Ceres (asteroid), 17
- Chamberlin, T. C., 235, 236
- Chaos, primaeval, density of, 202
- evolution from, 202, 204, 229, 230
- Charlier, C. V. L., 67
- Clusters, globular, 63, 64, 68, 213, 216
- moving, 39, 173, 216, 217
- Coal, combustion of, 175, 191
- Coal sack, 30
- Comets, 247, 251
- origin of, 238
- Condensation-chamber of C. T. R. Wilson, 113, 117
- Condensations in a gas, 198, 200, 203, 209, 237
- Configurations of rotating masses, 221
- Conservation, of angular momentum, 205, 217, 232
- of energy, 99, 189, 326, 328
- of matter, 189
- Constellations, 36, 39
- Cooke, H. L., 143
- Copernican astronomy, 3, 5, 6, 27, 32
- Copernicus, 3
- Creation, of matter, 336
- of universe, 79, 337
- Crookes, Sir W., 106
- Cycles and epicycles (Ptolemaic), 2, 3, 4
- Cyclic processes in nature, 325, 329, 331
- δ Cephei, 56, 223
- δ-rays, 113
- Darwin, Sir George, 224
- de Sitter, cosmology of, 79 ff., 84, 86, 174
- Democritus, 93
- Density, of matter in space, 77, 331, 332
- of nebulae, 208
- of stars, 265-8, 273, 282
- Diameters of stars, 260, 263-8, 272, 277-80
- Diffraction grating, 114
- Dimensions, of earth, 34
- of galactic system, 65
- of solar system, 20, 34
- of universe, 77, 83, 86, 87
- Discontinuity, in physics, 124 ff.
- of matter, 93
- Displacements of spectral lines, (de Sitter), 81
- (Doppler), 52
- (Einstein), 78, 323
- Distances, of globular clusters, 63
- of nebulae, 71, 73
- of stars, 33, 35, 36, 61, 62, 63
- Doppler effect, 52
- Dwarf and Giant stars, 276
- Dwarfs, white, 280, 283, 284, 292, 317, 319, 320, 322, 323, 335
- Earth, age of, 14, 151, 155, 173, 247
- as a planet, 16, 19, 230, 237, 243
- birth of, 237, 243
- dimensions of, 34
- future of, 225, 226, 250, 346, 352
- -moon system, 34, 225, 226, 240, 243, 250
- orbit of, 35, 36, 227, 346
- Eccentricity of binary orbits, 171
- of ellipse (defined), 46
- Eclipsing binaries, 54, 55, 56, 58
- Eddington, A. S., 67, 84, 179, 184, 187, 224, 287, 288, 295
- Einstein, A., (Cosmology), 74, 77, 79, 84
- (Gravitation), 45, 75, 79, 161
- (Quantum theory), 124, 126, 127
- (Relativity), 74 ff., 186, 261
- Electricity, positive and negative, 107
- attraction and repulsion, 107, 129
- Electromagnetic energy, 120, 121
- Electron, 107, 112, 119, 121
- orbits in atom, 108, 128
- Ellipse, defined, 46
- as atomic orbit, 129
- as gravitational orbit, 46, 47, 227
- Ellis, C. D., 139
- Emden, R., 286, 288
- Energy, 98, 120, 189, 326 ff.
- availability of, 326, 328
- conservation of, 99, 189
- source of stellar, 184
- weight of, 120
- Epicycles, 2, 3, 4
- Equipartition of energy, in a gas, 156
- stellar, 160, 164, 170, 172
- Eros, 34
- Ether, existence of, 338
- Evaporation, 94
- Evening stars, 17
- Evolution, from primaeval chaos, 202, 205, 229, 230
- stellar, 313 ff.
- Expanding universe, 84, 86 ff.
- Extra-galactic nebulae, 30, 70, 82
- densities of, 208
- distance of, 71, 82
- evolution of, 204 ff. and Plates XVI to XXI in order
- number of, 72
- rotation of, 205, 206
- size of, 31
- velocities of, 82, 84, 86
- weights of, 71, 215
- Faraday, M., 122
- Final end of universe, 329 ff.
- Fireball, 248
- Fission of stars, 169, 217, 219, 222, 229
- Fizeau, H. L., 261
- Fluorescence, 115, 327
- Fraunhofer, J. von, 105
- Free-path of molecules, 98
- Frequency of radiation, 115, 126, 127
- Full radiator, 123, 255, 261
- Galactic latitude and longitude, 24, 25
- Galactic nebulae, 29, Plates III (p. 29), VI (p. 37), VII (p. 44)
- Galactic system of stars, 23, 25, 65 ff., 211
- number of, 68, 69, 215
- rotation of, 66 ff., 214
- weight of, 69, 215
- Galileo, 1, 3, 4, 5, 8, 16, 24
- Galle, J. G., 19
- Gaseous masses in rotation, 206, 221
- Gaseous state, nature of, 95
- equipartition of energy in, 156
- Gaunt, J. A., 309
- Geodesy, 34
- Geology, 150, 152
- Gerasimovič, B. P., 321
- Giant and Dwarf stars (defined), 276
- Giant stars, internal constitution, 273, 290, 291, 310, 319
- Globular clusters, 63, 65, 213, 216 and Plate IX (p. 63)
- origin of, 216
- shape of, 213
- Goldsbrough, G. R., 250
- Graham, T., 158
- Gravitation, law of, 41, 45, 78, 161
- cause of, 76
- Gravitational instability, 197, 210, 237, 245, 246
- Great Bear (cluster), 173, 216, 217
- (constellation), 32, 39
- Great nebulae, see Extra-galactic nebulae
- H.D. 1337, see Pearce’s star
- Halley, E., 151
- Halley’s comet, 247, 251
- Halm, J., 163
- Hayford, J. F., 34
- Heat, nature of, 100
- effect of, on electrical structures, 141, 144
- transport of, in a star, 307
- Heat-death, 329, 330
- Helium atom, 110, 119, 185, 305
- Helmholtz, H., 177, 285
- Henderson, T., 33
- Herschel, Sir John, 23, 24, 211
- Herschel, Sir William, 18, 23, 24, 25, 26, 28, 65, 70, 211
- Hertzsprung, E., 59, 223, 275
- Hesperus, 17
- Hess, V. F., 143
- Highly penetrating radiation, 143, 144, 191, 298, 299
- Hinks, A. R., 65
- Holmes, A., 152
- Hubble, E., 71, 73, 77, 83, 84, 202, 204, 206, 208, 210
- Humason, M. L., 82
- Huyghens, C., 23
- Hydrogen atom, 110, 119, 130, 135, 146
- annihilation of, 146, 147, 192
- electron orbits in, 128, 130, 192
- Hyperbola, 46
- Instability, dynamical, 202
- gravitational, 197, 210, 237, 245, 246
- Interferometer, 261, 272
- Interstellar matter, 29, 30, 63
- Interstellar space, temperature of, 102
- Inverse square law, (electric), 129
- (gravitational), 44, 45, 47
- (luminosity), 24, 33
- Invisible radiation, 115, 258, 259
- Irregular nebulae, 206
- Irregular variables, 55, 58
- Island universes, 28, 31, 68
- Isotopes, 118
- Jeffreys, H., 155, 225, 226, 239
- Jupiter, 4, 16, 17, 19, 207
- birth of, 240 ff., 243, 244
- rotation of, 168, 225
- satellites of, 4, 23, 196, 240, 241, 243, 250
- size of, 17
- temperature of, 21
- weight of, 45
- K-ring of electrons in atom, 134, 138, 289, 291,
- 292, 302, 304, 318
- Kant, I., 176, 230, 231
- Kapteyn, J. C., 27, 65, 212, 214
- Kelvin, Lord, 177, 285
- Kepler, J., 5, 33, 46
- Klein, O., 146, 148
- Kolhörster, W., 143
- Kramers, H. A., 309, 310
- Kruger 60, 48, 278, 279, 280, 317
- system of, 267, 279, 280
- L-ring of electrons in atom, 134, 138, 289, 292, 302
- Lalande 21185, 36, 265
- Lane’s law, 286
- Laplace, P. S., 230, 233 ff.
- nebular hypothesis of, 230, 231, 232 ff.
- Lead, radio-active, 154
- Leavitt, Miss, 57
- Lemaître, G., 84, 86, 174
- Lenard, P., 106
- Leonid shooting-stars, 250
- Leslie, Sir John, 158
- Leucippus, 93
- Leverrier, U. J. J., 18, 19
- Life in solar system, 341
- in universe, 340, 342, 345
- on Earth, 12, 342, 345
- on Mars, 343
- on Venus, 344, 347
- Light, nature and composition of, 37, 50, 114
- speed of, 37, 115
- wave-length of, 115, 138
- Light-year, 37
- Lindblad, B., 67, 69
- Lippershey, 1
- Liquid masses in rotation, 219 ff.
- Liquid stars, 222, 296 ff., 300, 304, 310
- Lives of stars, see Stars
- Lockyer, Sir N., 314
- Long-period variables, 56, 58, 61, 271, 319
- Lowell, P., 19
- Lucifer, 17
- Lucretius, 93
- Luminosity of stars, 48, 49, 179, 269, 278, 279, 280
- M-ring of electrons in atom, 134, 289, 292, 293, 302
- McLennan, J. C., 143
- Magellanic clouds, 57, 210 and Plate XXI (p. 214)
- Main-sequence stars, 279, 291, 295
- Major planets, 16, 17
- atmospheres on, 197
- Man’s life on earth: past, 12, 16
- future, 345 ff.
- Marius, 31
- Mars, 18, 19, 35
- atmosphere of, 196, 343
- birth of, 240, 243, 244
- life on, 343
- orbit of, 20, 239
- rotation of, 225
- satellites of, 240, 243, 250
- temperature of, 21
- Matter, annihilation of, 185, 191, 192, 315
- conservation of, 189
- Maxwell, J. C., 122, 157
- Mayer, R., 176
- Mercury, 4, 5, 16, 17, 19, 22, 35
- absence of satellites, 243
- atmosphere of, 196, 348
- birth of, 240, 243
- life on, 348
- orbit of, 20, 45, 239
- rotation of, 22, 224
- Meteor, 238, 247, 248
- Meteorite, 248
- Michelson, A. A., 261
- Milky way, 3, 23, 26, 27, 28, 30
- Millikan, R. A., 143, 148
- Minor planets, 16
- Molecule, 94
- collisions of, 97, 98, 102
- equipartition of energy, 156
- size of, 95
- speed of, 96, 195
- Moon, 4, 43
- atmosphere of, 196
- birth of, 243
- distance of, 34, 43
- eclipse of, 34
- future of, 225, 226, 251
- rotation of, 225
- Moore, J. H., 321
- Morning star, 17
- Moulton, F. R., 235, 236
- Moving clusters, 40, 173, 216
- shape of, 216, 217
- Munich 15040, 36, 264
- Nebulae, classification of, 28
- Nebulae, distance and size of, 31, 71, 72
- extra-galactic, 28, 30, 70, 73, 82, 204 ff.
- motions of, 82
- rotation of, 205
- weights of, 71, 204, 208, 215
- M 31, see Andromeda, Great Nebula in
- M 33, 71, 210 and Plate XX (p. 213)
- N.G.C. 4594, 71, 72, 204, 208 and Plate XV (p. 204)
- Nebulae, galactic, 29 and Plates III (p. 29),
- VI (p. 37), VII (p. 44)
- Nebulae, planetary, 29, 273, 321, 323 and Plate II (p. 28)
- Nebulae, spiral, 30, 236
- Nebular hypothesis of Laplace, 230, 231, 232 ff.
- Neptune, 16, 17, 18, 19
- birth of, 240, 243, 244
- rotation of, 225
- satellite of, 240, 243
- New stars (novae), 61, 351
- Newton, Sir Isaac, (cosmogony), 197, 203
- (distances of stars), 33
- (law of gravitation), 44, 45, 46, 161, 197
- (light and optics), 50, 105
- Nicholas of Cusa, 3
- Nishina, Y., 146, 148
- Novae, 61, 351
- Nucleus, atomic, see Atomic
- ο Ceti, 58, 272, 280
- ο₂ Eridani, 268, 278, 280
- Ο-type stars, 51, 321, 323
- Obscuring matter in galactic system, 24, 30
- Oort, J. H., 67, 84, 214
- Opacity of stellar matter, 309
- Orbit, of binary systems, 47, 167 ff., 224 ff.
- of earth, 34, 36, 227
- of moon, 34, 43, 226, 250
- of planets, 45, 46, 237, 239, 245
- of stars, 211, 213, 216
- Oresme, 2
- Orion, constellation of, 32, 39, 173
- Paneth, F., 247
- Parallactic measures of stellar distances, 33, 61, 63
- Parallactic motion, defined, 33
- Parallax, spectroscopic, 62, 303
- Pearce’s star (H.D. 1337), 49, 54, 317
- Period-luminosity law (Cepheid variables), 59-61
- Perrin, J., 159, 184
- Perseid shooting-stars, 251
- Phases of moon and inner planets, 4, 5
- Philolaus, 2
- Phosphoros, 17
- Photo-electric action, 128
- Photography in astronomy, 37
- Piazzi, G., 17
- Planck, M., 123, 124, 126, 255
- “Planet X,” 19
- Planetary motions, 36, 45, 46, 78
- Planetary nebulae, 29, 273, 321, 323 and Plate II (p. 28)
- Planetary orbits, 45, 46, 237, 245
- Planetesimal Hypothesis, 235, 236
- Planets, arrangement of, 16, 19, 240
- birth of (Laplace), 231, 234
- birth of (Tidal Theory), 237, 240, 244
- in the universe, 341, 349
- motions and orbits of, 36, 45, 46, 78, 237, 239, 245
- Plaskett, J. S., 67, 214
- Plaskett’s star (B.D. 6° 1309), 49, 55, 269, 270, 272
- Pleiades, 32, 39, 40, 173, 216
- Plummer, H. C., 223
- Pluto, 16, 18, 19, 20, 239, 240, 241, 243
- birth of, 240, 243
- temperature of, 20
- Poincaré, H., 66, 285, 338
- Poincaré’s theorem, 285, 291
- Pressure in a gas, 97
- in a star, 306
- of radiation, 120
- of radiation in a star, 290, 306
- Primaeval chaos, evolution from, 202, 205, 229, 230
- Proctor, R. A., 235
- Procyon, 48, 266, 278, 279, 280
- Proton, 119, 121
- Proxima Centauri, 36, 40, 264, 278
- Ptolemy, 2, 3, 4, 5, 6, 8, 31
- Pythagoras, 2, 3, 5, 13
- Quantum, defined, 126
- Quantum theory, 122 ff., 137 ff., 286, 330, 331
- Quotations, Arnold, Matthew, 5
- Bede, 7
- Bruno, Giordano, 3
- Cornford, Frances, 11
- Cusa, Nicholas of, 3
- Galileo, 5
- Meredith, George, 283
- Newton, Sir Isaac, 197
- Sackville-West, Victoria, 7
- Shakespeare, 193
- Radiation, 114 ff., 137 ff., 254 ff., 307
- distribution by wave-length, 253
- highly penetrating, 143, 144, 191, 298, 299
- mechanical effects of, 120, 137, 290, 306
- of sun, 55, 175, 256
- pressure of, 120;
- in a star, 290, 306
- visible and invisible, 258, 259
- wave-length of, 122, 255, 258
- weight of, 120, 122, 136
- Radio-activity, 110 ff., 153, 298
- Rainbow, 50, 51, 105
- Rayleigh, Lord, 94
- Redman, H. O., 277, 349
- Relativity, theory of, 74 ff., 186, 261, 323, 337
- Ring nebula in Lyra, 29, 274 and Plate II (p. 28)
- Rings of electrons, in atom, 134, 138, 289, 291 ff., 302, 304, 305
- Roche, E., 245, 249
- Roche’s limit, 246, 250, 251, 252
- Rosse, Lord, 30
- Rotating masses, of gas, 206, 221
- of liquid, 219, 221
- Rotating nebulae, 205
- Rotating systems of stars, 168, 213
- Rotation, of astronomical bodies, 168, 216
- of galaxy, 66 ff., 214
- of nebulae, 205
- of stars, 217
- Royds, T., 112
- Russell, H. N., 187, 229, 276, 293, 299, 314
- Russell diagram, 276, 277, 278, 282, 283, 291,
- 295, 302, 303, 314, 338
- Rutherford, Sir E., 107, 111, 112, 117, 143, 154
- S Doradus, 182, 269, 270
- St John, C. E., 343, 344
- Salinity of oceans, 151
- Sampson, R. A., 17, 308
- Satellites, atmospheres on, 196
- birth of (Laplace), 231
- birth of (Tidal Theory), 241, 243, 246
- discovery of, 23
- Saturn, 16, 17, 18, 19, 32, 45
- birth of, 240, 242, 243
- rings of, 226, 231, 246, 247, 250
- rotation of, 225
- satellites of, 23, 196, 240, 241 ff., 250
- temperature of, 21
- Schrödinger, E., 305
- Schwarzschild, K., 308
- Seares, F. H., 26, 163, 281, 282
- Sedimentation, 151
- Shapley, H., 26, 59, 63, 65, 213, 216, 223, 247
- Shooting-stars, nature of, 176, 247
- origin of, 238, 247
- swarms of, 247, 248, 251
- Sirius, 36, 48, 259, 278, 279, 280, 316
- system of, 265
- Sirius B, 48, 262, 280, 292
- Soddy, F., 111
- Solar spectrum, 51, 105, 125, 256
- Solar system, arrangement of, Bode’s law, 19
- arrangement of (Copernican), 3, 5, 6, 27, 32
- arrangement of (Ptolemaic), 2, 4, 6, 8, 31
- atmospheres in, 194 ff., 343, 344, 347
- orbits in, 45, 46, 224 ff., 238
- origin of, 230 ff.
- Sound, 96, 198
- Spectra, stellar, 50, 125, 130 and Plate VIII (p. 51).
- See also Displacements
- Spectral types, 51
- relation to stellar weights, 164
- relation to surface-temperatures, 257
- Spectroscope, 50
- Spectroscopic binaries, 52
- orbits of, 171, 172
- origin of, 169, 222, 223
- Spectroscopic parallaxes, 62, 303
- Spectroscopic velocities, 50
- Spectroscopy, 105
- Spectrum, 50
- of sun, 50, 105, 125, 256
- Spherical nebulae, 207, 218, 219
- Spiral nebulae, 30, 236
- arms of, 236
- Stability of stellar structures, 295, 296, 300 ff.
- Stars, ages of, 84, 155, 167, 173, 174, 186
- arrangement of, 24, 65
- birth of, 209
- density of, 263 ff., 273, 282, 292
- diameters of, 260 ff., 277, 278, 321
- distances of, 31, 35, 37
- evolution of, 313 ff.
- internal constitution of, 285 ff.
- internal temperatures of, 286
- liquid, 222, 296 ff., 298, 301, 310
- luminosity of, 49, 179, 180, 269
- motions of, 36, 50, 66 ff., 164, 212, 213
- number of, 68, 69, 88
- spectra of, 51, 125, 130 and Plate VIII (p. 51).
- See also Displacements
- stability of, 295, 296, 300 ff.
- surface-temperatures of, 254, 257, 263 ff., 270, 271
- variable, 55 ff., 223
- weights of, 46, 48, 49, 164, 179, 268, 280 ff.
- Star-streaming, 212, 214
- Statistical methods in astronomy, 212, 213
- Stellar, see Stars
- Struve, Otto, 223
- Struve, W., 33
- Sun, age of, 181, 184
- candle-power of, 55
- distance from earth, 34, 227, 346
- future of, 348, 350
- internal constitution of, 286, 290
- internal temperature of, 286, 288
- loss of weight of, 178, 227, 346
- past history of, 180
- position in galactic system, 26, 66
- radiation of, 55, 175, 189, 190
- rotation of, 168, 205, 245
- surface-temperature of, 256
- Surface-temperatures of planets, 21 ff., 346, 347
- Surface-temperatures of stars, 254, 257, 263 ff., 270, 271
- of sun, 256
- Taylor’s comet, 251
- Telescope, 1
- Galileo’s, 2, 13
- Herschels’, 25
- Lord Rosse’s, 30
- 100-inch, 2, 20, 68, 72, 73
- 200-inch, 2, 73
- Temperature, scale of, 102
- Temperature-radiation, 140, 255
- Thermodynamics, 326 ff.
- first and second laws of, 326, 328
- Thomson, Sir J. J., 106
- Tidal friction, 224 ff.
- Tidal theory of solar system, 236 ff.
- Tides in binary stars, 224, 226
- Titan (satellite of Saturn), 23, 196
- Transit of Venus, 34
- Transport of energy in a star, 307
- Ultra-violet radiation, 116, 143, 144
- Universe, age of, 334, 336
- apparent expansion of, 84, 86 ff.
- beginning of, 77, 332 ff.
- final end of, 329 ff.
- size of, 77, 84, 87
- structure of, 74 ff., 87
- Uranium atom, 110
- disintegration of, 116, 121, 153
- Uranus, 16, 17, 18, 19, 20
- birth of, 240, 243, 244
- rotation of, 225
- satellites of, 23, 240, 243, 244
- temperature of, 21
- V Puppis, 278, 317
- van Maanen, A., 273
- van Maanen’s star, 268, 274, 278, 292
- van Rhijn, P. J., 26
- Variable stars, 55 ff., 222, 271, 319
- Vega (α Lyrae), 33
- Velocities of stars, 36, 68, 163 ff.
- Venus, 4, 5, 16, 17, 19, 34
- absence of satellites, 243
- atmosphere on, 197, 344
- birth of, 240, 243
- life on, 344, 347
- phases of, 4, 5
- rotation of, 224
- temperature of, 22, 347
- transit of, 34
- Virgo, nebula N.G.C. 4594 in, 71, 72, 204, 208
- and Plate XV (p. 204)
- Visual binaries, orbits of, 170, 171
- origin of, 169, 284
- Wave-length of radiation, 115, 122
- Wave-mechanics, 136, 305
- White dwarf stars, 280, 283, 288, 317, 318,
- 319, 320, 323, 348, 349
- Wilson, C. T. R., 113, 117
- Wireless transmission, 115
- Wolf 359, 36, 264, 269, 270
- X-rays, 116, 138, 144, 307, 311
- Zero (absolute) of temperature, 102
- Zodiacal light, 238
- Zwicky, F., 87
About This Book
The text surveys modern astronomy for general readers, explaining observational instruments and theoretical ideas used to study celestial and subatomic phenomena. It guides readers through sky exploration, atomic physics as it relates to astrophysics, cosmic chronology, galactic structure, stellar properties, and the processes of cosmic formation and dissolution. Special attention is given to cosmogony and evolution, with updated discussions of recent discoveries such as a newly identified outer planet, galactic rotation, and the apparent expansion of the universe, illustrated by plates and descriptive explanations.