Equinox and equator determinations from hypothetical minor planet observations

Abstract

Hypothetical observations of minor planets 1, 2, 3, 4, 6, 7, 8, 9, and 15 were computed for a ten year observing period commencing 2 Jan. 1980. The mean errors of the equinox and equator corrections were determined versus: the distribution of clear nights during the year; the length of the observing program; the number of minor planets included in the program; and the elongation from the Sun. It is concluded that the equinox and equator are best determined by: choice of a site with a minimum of 60% clear nights well distributed throughout the year; an observing program that lasts a minimum of four years, but that little is gained by extension of the program to more than ten years; inclusion of a minimum of four or five minor planets in the program, but that more than nine is not necessary; that the best four minor planets to use are numbers 1, 4, 7, and 15; and that observations should be made as far from opposition as possible, but that it is not essential to observe beyond quadrature.