An analysis of lunar occultations in the years 1943-1974 for corrections to the constants in Brown's theory, the right ascension system of the FK4, and Watts' lunar-profile datum
The times of 62 000 occultations of stars by the Moon observed during 1943–74 are analysed to determine corrections to the lunar ephemeris j = 2 (based on Brown's theory), the right ascension system of the fundamental star catalogue FK4, and the datum of the lunar-profile in Watts' charts. The method of reduction and analysis of the occultations is given in some detail. The value of |${-13}^{\prime\prime}\,{T}^{2}$| is adopted for the tidal term in the Moon's mean longitude and no clear evidence is found for any divergence between the dynamical and atomic time-scales. After removing all the corrections found in this analysis, quasi-periodic fluctuations – amounting to 0ʺ.2 – still remain in the residuals: these are ascribed to the truncation of planetary terms in Brown's theory.