Some Results From Visual Binary Orbits

Abstract

Presently orbits of nearly 700 objects are available, covering a considerable range of periods and other parameters, and — naturally — differing also with regard to reliability. Not too many cases, perhaps 25, meet first-class standards so that the elements can be termed ‘definitive’, that is to say, extensive data of good quality determine the elements within narrow limits, at least one-and-a-half revolutions are covered, and the semiaxis major is large enough to render its relative uncertainty small. These objects are nearby systems, most of them have good trigonometric parallaxes, and they supply an important part of the mass data.