Uranus - The rings are black

An investigation is conducted concerning the possibility that the rings about Uranus discovered during the occultation of star SAO 158687 might have been observed in earlier studies of the planet. It is concluded that in view of a very low estimate for the contrast of the rings seen against the disk, a detection of the rings by earlier visual observers is unlikely. It appears, however, that the Stratoscope II photographs recorded the projection of the rings on the disk of Uranus.