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Memoirs of the Royal Astronomical Society, Volum 3
Royal Astronomical Society
Visualització completa - 1827
Memoirs of the Royal Astronomical Society, Volum 11
Royal Astronomical Society
Visualització completa - 1840
angle aperture appeared Astronomer atmosphere August bodies bright calculated centre close clouds colour comet compared conjunction continued correction course dark Date determination diameter difficult direction disk distance double Earth east Eclipse edge effect elements equal error faint fully give given glass important inches interest Jupiter length less letter light limb lines longitude magnitude March marked Mars mass mean measures meteors micrometer minute Moon motion nearly nebula night noted noticed November object observations Observatory obtained orbit passed past period planet portion position preceding present probably produced Professor reference remarkable ring Royal satellites seen short side Society solar spectra spectrum stars stell surface taken telescope tion train visible
Pàgina 88 - All these facts are comprehended in the statement that in a constant temperature the absorption of a particle is equal to its radiation, and that for every description of light. It was also noticed that all coloured glasses ultimately lose their colour in the fire as they approach in temperature the coals around them, the explanation being, that while red glass, for instance, gives out a greenish light, it passes red light from the coals behind it, while it absorbs the green...
Pàgina 152 - Clusters (Cl.) are members of the Via Lactea, and are nearer to us than the average of its faint stars. 2. The Nebulae resolved and unresolved lie in general without the Via Lactea, which is therefore essentially stellar. 3. The visible universe is composed of systems, of which the Via Lactea, the two Nubecula, and the Nebulae, are the individuals, and which are themselves composed of stars (either simple, multiple, or in clusters) and of gaseous bodies of both regular and irregular outlines.
Pàgina 88 - The light of the star is compound, and has emanated from two different sources. Each light forms its own spectrum. In the instrument these spectra appear superposed. The principal spectrum is analogous to that of the sun, and is evidently formed by the light of an incandescent solid or liquid photosphere, which has suffered absorption by the vapours of an envelope cooler than itself. The second spectrum consists of a few bright lines, which indicate that the light by which it is formed was emitted...
Pàgina 88 - That these lines were not produced by the portion of the earth's atmosphere through which the light of Mars had passed, was shown by the absence of similar lines in the spectrum of the moon, which, at-the time of observation, had a smaller altitude than Mars.
Pàgina 88 - This observation was sufficient to solve the long-agitated inquiry in reference to this object at least, and to show that it was not a group of stars, but a true nebula. A spectrum of this character, so far as our knowledge at present extends, can be produced only by light which has emanated from matter in the state of gas.
Pàgina 88 - ... with particular portions of the planetary surface. The evidence we possess at present appears to support the opinion that the planet's distinctive colour has its origin in the material of which some parts of its surface are composed. Mr. Lockyer's observation, that the colour is most intense when the planet's atmosphere is free from clouds, obviously admits of an interpretation in accordance with this view.
Pàgina 144 - Mariners 6 and 7 have been used to obtain values for the ratio of the mass of the Earth to that of the Moon which are in substantial agreement with those determined from other Mariner and Pioneer spacecraft.
Pàgina 88 - ... have its temperature raised by light from the source, of the precise quality in question. In the atmosphere around the sun, therefore, there must be present vapour of sodium, which, according to the mechanical explanation thus suggested, being particularly opake for light of that quality, prevents such of it as is emitted from the sun from penetrating to any considerable distance through the surrounding atmosphere.
Pàgina 88 - ... and map them all, the labour of months would barely suffice. The physical result of all this scrupulous and conscientious care was to discover the fact, or it may be to confirm the suspicion, that those mysterious lights with which the firmament is spangled, are in strict reality worlds fashioned in their material constitution, at least not altogether differently from the fashion of the little orb on which we live ; beyond the question of a doubt they are proved by the investigations of our Medallists...
Pàgina 88 - ... all constructed upon the same plan as our sun, and are composed of matter identical, at least in part, with the materials of our system. " The differences which exist between the stars are of the lower order of differences of particular adaptation, or special modification, and not differences of the higher order of distinct plans of structure. " There is, therefore, a probability that these stars, which are analogous to our sun in structure, fulfil an analogous purpose, and are, like our sun,...