Our Astronomical Column

Abstract

NEW ANNUAL TERM IN THE VARIATION OF LATITUDE.—In the Astronomical Journal, vol. xxii. pp. 107-108, Prof. H. Kimura announces that from a detailed examination of the observations taken for variation of latitude he has detected a periodicity in the residuals obtained, which appears to indicate the existence of a hitherto unrecognised annual component. Most of the observations were collected in Prof. Albrecht's report in the Astronomische Nachrichten, No. 3734. The maximum amplitude of the new term is about 0″.03. At present it is impossible to examine the dependence of this element on geographical position, as the materials have been combined from all stations between φ = 60° N. and φ = 21° N., and the term as found would correspond to a mean latitude 42° N. A future series of observations in different parallels will possibly settle if the new component is a function of the latitude. From the variation curve it appears that the new term has zero values at 0.33 and 0.85, maximum at 0.0 and minimum at 0.57; a noticeable feature of this is that the zeroes lie near the equinoxes, the maxima and minima near the solstices.