ラグランジュ点
Telesto is co-orbital with Tethys, residing in Tethys' leading Lagrangian point (). This relationship was first identified by Seidelmann "et al." in 1981. Another moon, Calypso, resides in the other (trailing) Lagrangian point of Tethys, 60 degrees in the other direction from Tethys. The Saturnian system has two additional trojan moons.