Role of the F Ring During the Ring Plane Crossings in 1995-96

F. Poulet (Obs. Paris), B. Sicardy (Obs. Paris, Univ./IUF Paris 6)

We will examine the role played by the Saturn F ring during the plane crossings in 1995-96. Emphasis is given on the ring thickness and the small inner objects.

We model the photometric data obtained during the Earth ring plane crossings and the solar crossing. The data from the Earth ring plane crossing could give lower limit on the physical height of the F ring (Poulet and Sicardy, BAAS 28, 1124). New constraints from the solar crossing in November 1995 are obtained, in order to explain both the August and November 1995 profiles.

New detections of four small inner objects were made, allowing us to cover several revolutions of two objects. We use the photometric model to infer the nature of these new objects. We also propose that they are composed of regolith ejecta and result from collisions between small moonlets. From the number and optical depth, we derive the lifetimes of the new objects and we estimate the total cross-sectionnal area and sizes of the unseen parent objects to be consistent with observations of the F ring region.