Determination of Stellar Parallax, Volume 1 |
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Common terms and phrases
175.8 unless otherwise 61 Cygni absolute magnitude accidental error accuracy Approximate solution Assumed P. M. Average residual average value bold-face type Bonn Bonn Durchmusterung bright stars Catalogue column comparison-stars computed parallaxes Corrected derived discordance double stars Dyson's method epochs Equations of condition errors of observation faint stars Flint corr given groups H Approximate H Plate Harvard heliometer Hour-angle Hr.-ang images intervals of 175.8 Kapteyn Lalande mate solution mean parallax mean-square measured coördinates Measurer's Monthly Notices musterung Normal equations number of stars Numbers in bold-face Observatory observed parallaxes Observed with Color-screen Observer's obtained P. M. and Ax pair parallax-star photographic magnitude plate-constants probable error quantities reduced regard to sign regardless of sign réseau intervals réseau lines right ascension second of arc spectral type standard star-image stars of Type systematic error type are negative visual magnitude Weight x 0-c x
Popular passages
Page 101 - The great historical epidemics have diminished in intensity ; and there appears to be no reason why they should not be ultimately suppressed, with the advances of the population among which they take their rise.
Page 1 - Determinations of Stellar Parallax, based upon photographs taken at the Cambridge Observatory by Arthur R. Hinks and the writer ; with Magnitudes and Spectra determined at the Harvard College Observatory under the direction of Prof. EC Pickering. Quarto, vi+142 pages ............. $2.00 n 148.
Page 7 - ... solution f. * Single word to denote space vacated by water. t From the elementary hydrokinetics of the motion of an ellipsoid through an inviscid incompressible fluid, originated by Green, who first gave the solution for the case of translational motion of the ellipsoid, we know that, if 9 denotes the angle between the normal to the surface at any point and the axis of an oblate ellipsoid of revolution, of which the equatorial and polar semiaxes are a, b, the velocity of the fluid flowing over...
Page 85 - Vol. 41, p. 146. 15. Russell. Determinations of Stellar Parallax, Carnegie Institution of Washington Publication No. 147, p. 76. Also, Astronomical Journal, Vol. XXVI, p. 149, p. 85. Russell states, " there can be little doubt that the parallax found in the present work is too great by o".08 or thereabouts.
Page 3 - ... out Prof. Kapteyn's idea of accumulating exposures at successive epochs, upon the same plate, and we were fully convinced that all the plates should be taken on the meridian. We desired to keep two objects in view — namely, ( i ) to secure the most advantageous relation between the amount of labour to be expended and the probable accuracy of the results to be achieved, and (2) to eliminate all known sources of systematic error. Under the circumstances we decided to take separate plates at each...
Page 41 - M , the constants a, b, and c were determined by a least-squares solution. The weight of each equation was taken equal to the number of stars involved in its determination. The values of the resulting constants, with their mean errors, all in thousandths of a second of arc, are as shown in Table I. We test the significance of the results for b and c, leaving the discussion of the significance of the a's to those who are familiar with the possible sources of constant systematic error. It would be...
Page 26 - The work of taking, measuring, and reducing the plates may be divided into two parts, one of which is independent of n, and the other proportional to it.
Page 51 - If they were entirely due to this cause, the mean proper-motion and parallax for each group should be in the inverse ratio of the square roots of their weights. In this way the quantities in the column headed "Expectation" are derived from the observed mean parallaxes.
Page 63 - TT is the parallax and 5/3 the difference of the refraction constant, relative to the mean of all the stars on the plate). The coefficients of 5/3 for the individual plates vary somewhat, without departing far from this average value.