| Discovery | |
|---|---|
| Discovered by | Edward Ashton, Brett J. Gladman |
| Discovery date | 2020 |
| Orbital characteristics [1] | |
| 18,235,500 km (11,331,000 mi) | |
| Eccentricity | 0.495 |
| 2.538 yrs (926.96 d) | |
| Inclination | 40.1° (to the ecliptic) |
| Satellite of | Saturn |
| Group | Gallic group |
| Physical characteristics | |
| 3 km | |
| 17.0 | |
S/2020 S 4 is a small and very faint natural satellite of Saturn. It was discovered by Edward Ashton, Brett J. Gladman, Jean-Marc Petit and Mike Alexandersen on June 24, 2020, and was announced on May 6, 2023 by the IAU Minor Planet Center after observations were collected over a long period of time to confirm the satellite's orbit that were taken between July 1, 2019 and July 9, 2021. [2]
S/2020 S 4 is a highly eccentric satellite with an eccentricity of 0.495, it orbits Saturn at an average distance of 18.2 million km and an orbital period of 2 and a half years, with an inclination of 40.1° to the ecliptic, suggesting that it belongs to the Gallic group. [1] However, sometimes its moon group is disputed, and it may be included in the Inuit group. [3] [4] It has been suggested that it was a fragment piece of Siarnaq that broke off a long time ago in a time-span of a few thousand years. [3]
The orbit of S/2020 S 4 is liberating in accordance of von Zeipel–Lidov–Kozai effect. [5]
S/2020 S 4 is estimated to be 3 km in diameter and has an absolute magnitude of 17, making it one of the faintest moons of Saturn. [1] Scott S. Sheppard and Tilmann Denk on the other hand, estimated it to be 2 km and 2 and a quarter km, respectively. [4] [3] If these estimates were true, it would make S/2020 S 4 one of the smallest known irregular moons of Saturn. [3]