The 10 February 1977 lunar occultation of Uranus. Radius, limb darkening, and polar brightening at 6900 A

Abstract

Contact timings, corrected for lunar limb effects, indicate an equatorial radius of 25700 + or - 500 km for the visible disk for Uranus. A modified Minnaert function is used to model limb darkening and polar brightening. Least squares fits to the observed light curve indicate that Uranus is slightly limb darkened in the passband of the observations (450 A FWHM centered near 6900 A) and that polar brightening is present