The Astrophysical Journal, Volume 12University of Chicago Press, 1900 "Letters to the Editor" issued as Part 2 and separately paged from v. 148, 1967. Beginning in 2009, the Letters published only online. |
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Common terms and phrases
angle aperture apparatus appear Astronomical ASTROPHYSICAL JOURNAL atmosphere axis bands bolometer bright lines camera chromosphere cluster coelostat collimator color screen comparison continuous spectrum corona curve Cusp Cygni dark lines diameter discharge distance double stars E. E. BARNARD eclipse effect electrodes emission equatorial exposure faint field flash focal length focus Fraunhofer lines galactic given heat hydrogen inches inner corona instrument intensity investigation Keeler lens Lick Observatory light magnitude maxima measures mercury Milky minutes nebula nitrogen objective observations obtained photographs photosphere plane plate-holder plates polar position pressure prism Professor prominences radiation rays reflected refraction region ring Rowland's self-induction shadow bands sharp slit sodium solar spark spectra spectrograph spectroscope SS Cygni stellar Sun's taken telescope temperature third contact tion totality triplets tube ultra-violet vapor variable stars velocity violet visible visual wave-lengths Yerkes Observatory ΙΟ
Popular passages
Page 143 - In such cases it is equally impossible not to perceive that we are looking through a sheet of stars nearly of a size, and of no great thickness compared with the distance which separates them from us.
Page 144 - Thus when we see, as in the coal-sack, a sharply defined oval space free from stars, insulated in the midst of a uniform band of not much more than twice its breadth, it would seem much less probable that a conical or tubular hollow traverses the whole of a starry stratum, continuously extended from the eye outwards, than that a distant mass of comparatively moderate thickness should be simply perforated from side to side...
Page 146 - Neither can we without obvious improbability refuse to admit that the long lateral offsets which at so many places quit the main stream and run out to great distances, are either planes seen edgeways, or the convexities of curved surfaces viewed tangentially, rather than cylindrical or columnar excrescences bristling up obliquely from the general leveL...
Page 276 - Lecture for 1885, of what we knew up to that time of the sun's corona, I was led to the conclusion that the corona is essentially a phenomenon similar in the cause of its formation to the tails of comets — namely, that it consists for the most part probably of matter going from the sun under the action of a force, possibly electrical, which varies as the surface, and can therefore in the case of highly attenuated matter easily master the force of gravity even near the sun. Though many of the coronal...
Page 240 - ... full and undisturbed. Withal, Professor Keeler's administration was so kind and so gentle — and yet so effective — that the reins of government were seldom seen and never felt. The elements of his successes are simple, and plainly in view. His openness and honesty of character, his willingness and quickness to see the other man's point of view, his strong appreciation of the humorous, as well as the serious, and, above all, his abounding good sense — these traits made his companionship...
Page 239 - They may be briefly summarized as follows: — 1. Many thousands of unrecorded nebulae exist in the sky. A conservative estimate places the number within reach of the Crossley reflector at about 120,000. The number of nebulae in our catalogues is but a small fraction of this.
Page 243 - ... Ibid., Vol. II, p. 929. The Spectroscope of the Allegheny Observatory. Ibid., Vol. XII, p. 40 ; London Engineering, May 12, 1893. Spectrum of Holmes
Page 244 - The Design of Astronomical Spectroscopes. Ibid., vol. I, p. 248. "The Source and Mode of Solar Energy throughout the Universe.
Page 238 - Observatory has perhaps the poorest location of any observatory in this country for spectroscopic work. But in spite of this disadvantage Keeler's investigations continued and promoted the splendid reputation established for the observatory by his predecessor. He comprehended the possibilities and limitations of his situation and his means, and adapted himself to them. His spectroscopic researches were largely confined to the orange, yellow and green regions of the spectrum, since these would be...
Page 70 - the corona is effectively cooler than the bolometer, and appears, therefore, neither to reflect much light from the sun, nor, chiefly by virtue of a high temperature, to give light of its own, but seems rather to be giving light in a manner not associated with a high temperature, or at least with the preponderance of infra-red rays usual in the spectra of hot bodies.