Galilean satellites - Observations of mutual occultations and eclipses in 1973

Seven Galilean satellite mutual events, two occultations and two eclipses of Europa and three eclipses of Io, were observed at three wavelengths (0.35, 0.50, 0.91 micrometers) with a time resolution of 0.1 sec. Preliminary model fits to the light curves are presented. Model satellites with different albedo distributions (uniform disk, bright solar caps, bright quadrant) are used in generating model occultation and eclipse curves to demonstrate the sensitivity of observed light curves to the brightness distribution on the surface of the occulted or eclipsed satellite. At the present the observations yield no conclusive information of the limb-darkening of Io. The best data for Europa indicate that the satellite is limb-darkened at both 0.50 and 0.91 micrometers.