La velocidad del sistema δ Librae

Abstract

In order to resolve the problem of the difference in the system of δ Librae as found when comparing observations made at Allegheny and at Michigan, all the available material, including the Mount Wilson material secured a few years ago and analyzed by two of the authors (J. Sahade and A .Hernández), was measured with the Grant line spectrum comparator of the Department of Astronomy of the Indiana University. When the measurements were reduced (they were made on only one direction of the carriage) it was found that there were systematic differences between the velocities from diffuse and from sharp lines. The latter are in keeping with the velocities obtained with the conventional type of comparators. The preliminary analysis of the results that are consistent suggest that the announced difference in the system velocity at two epochs has no significance and resulted only from the original method of measurement and reduction.