Calypso

…Tethys’s two co-orbiters, Telesto and Calypso, are located at the stable Lagrangian points along Tethys’s orbit, leading and following Tethys by 60°, respectively, analogous to the Trojan asteroids in Jupiter’s orbit. Dione’s Trojan-like companions, Helene and Polydeuces, lead and follow it by 60°, respectively, on average.

…two tiny moons, Telesto and Calypso (named for daughters of Titans), that maintain gravitationally stable positions along its orbit, analogous to Jupiter’s Trojan asteroids. Telesto precedes Tethys by 60°, and Calypso follows by 60°. (For comparative data about Tethys, its companions, and other Saturnian satellites, see the table.)