 Telesto as seen by the Cassini probe on 11 October 2005 | |
| Discovery | |
|---|---|
| Discovered by |
|
| Discovery date | April 8, 1980 |
| Designations | |
Designation | Saturn XIII |
| Pronunciation | /təˈlɛstoʊ/ |
Named after | Τελεστώ Telestō |
| Tethys B S/1980 S 13 | |
| Adjectives | Telestoan /tɛləˈstoʊ.ən/ or Telestoian /tɛləˈstoʊ.iən/ |
| Orbital characteristics | |
| 295000 km[1] | |
| Eccentricity | 0.001[1] |
| 1.887802 d[1] | |
| Inclination | 1.19° (to Saturn's equator) |
| Satellite of | Saturn |
| Group | L4 Tethys trojan |
| Physical characteristics | |
| Dimensions | 33.2 × 23.4 × 19.2 km (± 0.6 × 0.6 × 0.4 km)[2]: 2 |
Mean diameter | 24.6±0.6 km[2]: 2 |
| Volume | 7795 km3[a] |
| Mass | ≈ 4×1015 kg (assumed; unmeasured)[b] |
Mean density | ≈ 0.5 g/cm3 (assumed; unmeasured)[2]: 3 |
| ≈ 0.0011–0.0014 m/s2[2]: 3 | |
| ≈ 0.006 km/s at longest axis to ≈ 0.007 km/s at poles | |
| zero | |
| 18.7 [3] | |
Telesto /təˈlɛstoʊ/ is a moon of Saturn. It was discovered by Smith, Reitsema, Larson and Fountain in 1980 from ground-based observations, and was provisionally designated S/1980 S 13.[4] In the following months, several other apparitions were observed: S/1980 S 24,[5] S/1980 S 33,[6] and S/1981 S 1.[7]
In 1983 it was officially named after Telesto of Greek mythology.[c] It is also designated as Saturn XIII or Tethys B.
Telesto is co-orbital with Tethys, residing in Tethys' leading Lagrangian point (L4). This relationship was first identified by Seidelmann et al. in 1981.[8] 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.
