Monochromatic phase curves and albedos for the lunar disk

Abstract

Photoelectric observations of the entire lunar disk were made in 1964-1965 over phase angles 6' i 120' in nine narrow bands (0.35-1.0 ) and in UBV Phase curves are presented as a function of wavelength; the results confirm a reddening with increasing phase angle found by previous investigators for particular areas. Observa- tions before full Moon appear systematically brighter ( < 0.1 mag in V) than points after at equivalent phase angles. Differences in spectral reflectivity between our data for 1964 and 1965, and also among earlier studies, are discussed, including the possibility of time-dependent emission (luminescence). Geometric albedos, phase coefficients, phase integrals, and Bond albedos are presented at all wavelengths, excluding any opposition effect. Values of the phase integral, traditionally assumed to be independent of wavelength, are found to increase with wavelength (0.53 <q ( )<0.68). The radiometric albedo of the Moon is estimated to be A * = 0.123+0.002.