Iocaste (moon)
Iocaste, also known as Jupiter XXIV, is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii including: David C. Jewitt, Yanga R. Fernandez, and Eugene Magnier led by Scott S. Sheppard in 2000, and given the temporary designation S/2000 J 3.
Iocaste imaged by the Canada-France-Hawaii Telescope in December 2001 | |
| Discovery | |
|---|---|
| Discovered by | Scott S. Sheppard David C. Jewitt Yanga R. Fernandez Eugene A. Magnier |
| Discovery site | Mauna Kea Observatory |
| Discovery date | 23 November 2000 |
| Designations | |
Designation | Jupiter XXIV |
| Pronunciation | /aɪoʊˈkæstiː/ |
Named after | Ιοκάστη Iokástē or Jocasta |
Alternative names | S/2000 J 3 |
| Adjectives | Iocastean /ˌaɪoʊkæˈstiːən/ |
| Orbital characteristics | |
| Epoch 17 December 2020 (JD 2459200.5) | |
| Observation arc | 17.39 yr (6,350 days) |
Semi-major axis | 0.1432617 AU (21,431,650 km) |
| Eccentricity | 0.3294908 |
Orbital period (sidereal) | –640.97 d |
Mean anomaly | 289.50565° |
Mean motion | 0° 33m 41.927s / day |
| Inclination | 149.42446° (to ecliptic) |
Longitude of ascending node | 343.53045° |
| 110.27239° | |
| Satellite of | Jupiter |
| Group | Ananke group |
| Physical characteristics | |
Mean diameter | 5 km |
Mean radius | 1.6 miles (2.6 km) |
| Albedo | 0.04 (assumed) |
| 21.8 | |
| 15.5 | |
Iocaste orbits Jupiter at an average distance of 20.723 million kilometers in 632 earth days, at an inclination of 147° to the ecliptic (146° to Jupiter's equator) with an eccentricity of 0.2874.
It was named in October 2002 after Jocasta, the mother/wife of Oedipus in Greek mythology. The name ending in "e" was chosen in accordance with the International Astronomical Union's policy for designating outer moons with retrograde orbits.
Iocaste belongs to the Ananke group, believed to be the remnants of a break-up of a captured heliocentric asteroid.
The satellite is about 5 kilometres in diameter and appears grey (colour indices B−V=0.63, R−V=0.36), similar to C-type asteroids.