Gerd (Saturn LVII), provisionally known as S/2004 S 25, is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, and Jan Kleyna on October 7, 2019 from observations taken between December 12, 2004 and March 22, 2007.[3] It was given its permanent designation in August 2021.[4] On 24 August 2022, it was officially named after Gerðr, a jötunn from Norse mythology.[5] She is married to Freyr and the personification of fertile soil.[6]
| Discovery[1] | |
|---|---|
| Discovered by | Sheppard et al. |
| Discovery date | 2019 |
| Designations | |
Named after | Gerðr |
| Saturn LVII S/2004 S 25 S8631e[2] | |
| Orbital characteristics[2] | |
| 20544500 km | |
| Eccentricity | 0.457 |
| −1095.0 days | |
| Inclination | 173.3° |
| Satellite of | Saturn |
| Group | Norse group |
| Physical characteristics | |
| 4+50% −30% km | |
| 25.2 | |
Gerd is about 4 kilometres in diameter, and orbits Saturn at an average distance of 21.174 Gm in 1150.69 days, at an inclination of 173° to the ecliptic, in a retrograde direction and with an eccentricity of 0.442.[3]
References
edit- ^ Discovery Circumstances from JPL
- ^ a b S.S. Sheppard (2019), Moons of Saturn, Carnegie Science, on line
- ^ a b "MPEC 2019-T132 : S/2004 S 25". minorplanetcenter.net. Retrieved 7 October 2019.
- ^ "M.P.C. 133821" (PDF). Minor Planet Center. International Astronomical Union. 10 August 2021. Retrieved 21 August 2021.
- ^ "Names Approved for 10 Small Satellites of Saturn". usgs.gov. USGS. 24 August 2022. Retrieved 30 August 2022.
- ^ "Planet and Satellite Names and Discoverers". usgs.gov. IAU WGPSN. Retrieved 30 August 2022.