Comparative analysis of the data of Saturn's photometry from ground-based observations and from the Hubble Space Telescope measurements.

Abstract

The results of a detailed photometry of Saturn from HST obtained in June 1991 were compared with photographic observations of Saturn in July 1991 made with 1-meter telescope at good image quality. The latitudinal variations of Minnaert's limb darkening coefficients derived from these observations are in very good agreement as well as the relationship between normal albedo and limb darkening. The latitudinal variations of zonal limb darkening in different spectral regions may be connected with noticeable differences of the mean sizes of the cloud particles at low and high latitudes and partially or especially with the altitudinal differences of the upper effective boundary of aerosol. The equivalent amount of H2 over this effective level varied from approximately 12 - 15 km-am at the latitudes 30 - 45 N to about 5 - 7 km-am near equator and at the latitudes >60°.