The Astrophysical Journal, Volume 23University of Chicago Press, 1906 "Letters to the Editor" issued as Part 2 and separately paged from v. 148, 1967. |
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absorption band amount angular aperture aperture apparatus appear asteroids Astronomical Astrophysical Journal atmosphere atom axis bolometer bright column comparison corona curve determined diameter DIAPHRAGM discharge-tube disk distance double E. E. BARNARD East West East eclipse effect electrons equations error exposure faint film fluorite focal length fourth-type stars Fraunhofer lines give given grating Guelma hydrogen hydrogen lines increase instrument intensity investigations Lick Observatory light lines luminosity magnetic magnitude mean measured method mirror motion nebula observations obtained optical orbit paper parallaxes period plate-holder position pressure prism Professor radial velocity radiation radius region reversal ring rotation Rowland selenium slit solar solution spectra spectrograph spectroheliograph spectroscope spot spectrum sun-spots Sun's taken telescope temperature tion totality trum tube ultra-violet Variable Variable Stars wave-length West East West Yerkes Observatory Zeeman effect ΙΟ μμ
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Page 315 - Total Eclipse of the Sun, May 18, 1901. Reports on the Dutch Expedition to Karang Sago, Sumatra, N '. 4 : Heat Radiation of the Sun during the Eclipse", by WH JULIUS.
Page 34 - that there is no fundamental difference between the general solar spectrum and that of the spots." If, in accordance with what appears to be his view (see the above quotation from his memoir), the spot spectrum is produced by a general increase in the intensity of the lines of the solar spectrum, no such differences in the relative intensities of the spot lines as are plainly shown in c c "fp o — 2 c '& •ft c U.
Page 238 - Thus the induced current is at all times directly proportional to the total change in the number of magnetic lines of force passing through the circuit. Besides, every induced current persists so long as the new number of lines of magnetic force through the circuit is not allowed to change. In the case of any particular ring K, the value of the current is . _ *'2« Hence ,. nk10-2Dda,k dNk wk — s = r- , 2T Lt JV' which shows that -,— is a constant.
Page 350 - SCENTED SOAPS PEARS' OTTO OF ROSE IS THE BEST. "All rights secured.
Page 202 - The pressure and purity of the gases, the shape and character of the discharge-tube, the material of the electrodes, and the time of exposure are all factors, which have undergone investigation. METHODS OF MEASUREMENT The methods used were two in number. The values of all the lines were first obtained by the two-slit method, and these values were then checked by obtaining the stronger lines in the second spectrum and comparing their positions with known iron lines in the first spectrum. For this...
Page 53 - Yerkes refractor. As stated in this paper, the most satisfactory form of spectroheliograph is that in which the instrument is moved as a whole, while the image of the Sun and the photographic plate are stationary. The first spectroheliograph of this type was constructed in 1893, from Mr. Hale's general design, by Toepfer, of Potsdam, and employed in some attempts to photograph the solar corona without an eclipse, from the summit of Mount Etna.
Page 6 - Snow telescope except under the conditions stated. As a matter of fact, however, very fair photographs can be obtained with the spectroheliograph at almost any time during a cool day, and in the early morning and late afternoon hours of a hot day without wind. It is only necessary to arrange the daily program of observations so that the spectroheliograph, which requires the finest definition, is used during the period when the seeing is best. Photographic work on the spectra of sun-spots follows,...
Page 244 - When the density becomes more and more pronounced, a correspondingly increased proportion of light will be produced while the atoms are close enough markedly to affect each other. There will then be three causes of broadening: a) The temperature line-of-sight motion. b) The line-of-sight motion due to the attractions and repulsions of the atoms — probably in many cases b) exceeds a). c) The mutually induced currents in the atoms. Both a) and b) will produce symmetrical broadening, but c), owing...