Catalogue of 2436 stars from observations with the reversible meridian circle, made at the Dominion Observatory, Ottawa, during the years 1911-1923

Abstract

This catalogue is the result of observations taken at Ottawa between the years 1911 and 1923. Primarily the program was undertaken to improve star positions needed in carrying out field observations for latitue and longitude in Canada. Right ascensions are determined differentially with a selected list of stas from Boss P.G.C. used as the fundamental catalogue. Declinations were computed from nadir readings with 45 degree 23' 39''. 0 used as a provisional latitude of the meridian circle. No correction for flexure was applied and Pulkowa refraction tables were used. Corrections for variation of latitude were taken from values given by the International Latitude Variation stations. Tables of pivot errors, circle division errors, etc., are given. Clamp errors were investigated and a solution from pole stars at upper and lower culmination gave as correction to the provisional latitude used </> = 45° 23' 38" ·67. A reversing prism was used with the eye-piece throughout the work. Tables give comparisons of the Ottawa values with those of Boss P.G.C., Eichelberger's positions for 1925 and the First Greenwich Catalogue for 1925.0.