Theory of motion of Saturn's coorbiting satellites

A simple analytic theory describing the 1:1 orbital resonance is presented and applied to Saturn's coorbiting pair, 1980S1 and 1980S3. These satellites are very small and can approach to within 15,000 km, but are prevented from passing each other by their mutual gravitational interaction. The long-term stability of the S1-S3 orbital configuration is discussed in this paper, and a tie between the 1966 and 1980 observations is established.