The Realm of the NebulaeNo modern astronomer made a more profound contribution to our understanding of the cosmos than did Edwin Hubble, who first conclusively demonstrated that the universe is expanding. Basing his theory on the observation of the change in distanct galaxies, called red shift, Hubble showed that this is a Doppler effect, or alteration in the wavelength of light, resulting from the rapid motion of celestial objects away from Earth. In 1935, Hubble described his principal observations and conclusions in the Silliman lectures at Yale University. These lectures were published the following year as "The Realm of the Nebulae," which quickly became a classic work. |
Contents
MAGNITUDEDIFFERENCES AND LUMINOSITYRATIOS | 11 |
THE EXPLORATION OF SPACE | 20 |
FAMILY TRAITS OF NEBULĘ | 36 |
DIAMETERLUMINOSITY RELATION | 51 |
SPECTRAL TYPES AND COLORS OF NEBULĘ | 53 |
RELATIVE FREQUENCIES OF NEBULAR TYPES | 55 |
THE DISTRIBUTION OF NEBULĘ | 58 |
DISTANCES OF NEBULĘ | 83 |
THE LOCAL GROUP | 124 |
MEMBERS OF THE LOCAL GROUP | 126 |
THE GENERAL FIELD | 152 |
ABSOLUTE MAGNITUDES OF VARIOUS TYPES OF NEBULĘ | 176 |
DIAMETERS OF NEBULĘ | 178 |
SPECTROGRAPHIC MASSES OF NEBULĘ | 180 |
THE REALM OF THE NEBULĘ | 182 |
| 203 | |
Other editions - View all
Common terms and phrases
100-inch reflector absolute magnitudes apparent faintness apparent luminosities apparent magnitude Astrophysical Journal average bright brighter brightest stars Cepheid variables Cepheids conspicuous constant criteria of distances density derived diameters dispersion elliptical nebulę extragalactic fainter field-nebulę galactic obscuration galactic system galaxies globular clusters Harvard College Observatory Hubble Humason images increase indicated intrinsic luminosities investigations irregular nebulę irregular variables island universes K-term known latitude light-years linear luminosity-function Lundmark Magellanic Clouds magni mean Messier Messier 32 miles/sec Milky million light-years nebu nebulosity normal novę nuclear region nucleus numbers of nebulę objects observable region Observatory parsecs peculiar motions photographic plates radial velocities red-shifts relative represent resolved nebulę rotation Shapley solar motion spectra spectral type spectrum stellar system surveys systematic tance telescopes theory tion tudes types uniform values variables velocity-distance relation velocity-shifts Virgo cluster volume of space Wilson Contr zone of avoidance