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 led by Scott S. Sheppard in 2000, and given the temporary designation S/2000 J 3.[5][1]

Not to be confused with the minor planet named 899 Jokaste.

Iocaste

Iocaste imaged by the Canada-France-Hawaii Telescope in December 2001
Discovery[1]
Discovered by	Scott S. Sheppard et al.
Discovery site	Mauna Kea Obs.
Discovery date	23 November 2000
Designations
Designation	Jupiter XXIV
Pronunciation	/aɪoʊˈkæstiː/
Named after	Jocasta (Ιοκάστη)
Alternative names	S/2000 J 3
Adjectives	Iocastean /ˌaɪoʊkæˈstiːən/[2]
Orbital characteristics [3]
Semi-major axis	21269000 km
Eccentricity	0.216
Orbital period	−631.5 days
Mean anomaly	129.8°
Inclination	149.4°
Longitude of ascending node	271.3°
Argument of perihelion	80.0°
Satellite of	Jupiter
Group	Ananke group
Physical characteristics
Mean diameter	5 km
Mass	1.9483×10^14 kg
Mean density	2.6 g/cm^3
Escape velocity	11  km/h[4]
Apparent magnitude	21.8

Iocaste orbits Jupiter at an average distance of 20.723 million kilometers in 609.427 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,[6] the mother/wife of Oedipus in Greek mythology.

Iocaste belongs to the Ananke group, believed to be the remnants of a break-up of a captured heliocentric asteroid.[7][8]

The satellite is about 5 kilometres in diameter[9] and appears grey (colour indices B−V=0.63, R−V=0.36), similar to C-type asteroids.[10]

References

1. Brian G. Marsden (January 5, 2001). "S/2000 J 2, S/2000 J 3, S/2000 J 4, S/2000 J 5, S/2000 J 6". International Astronomical Union Minor Planet Center.
2. Kin'ya Tsuruta (1996) Shiga Naoya's A Dark Night's Passing, p. 92
3. S.S. Sheppard (2019), Moons of Jupiter, Carnegie Science, on line
4. "Iocaste: By the Numbers". NASA. Archived from the original on April 12, 2016. Retrieved March 29, 2015.
5. Daniel W. E. Green (January 5, 2001). "Satellites of Jupiter". International Astronomical Union Central Bureau for Astronomical Telegrams.
6. Daniel W. E. Green (October 22, 2002). "Comet P/2002 T5 (Linear)". International Astronomical Union Central Bureau for Astronomical Telegrams.
7. Sheppard, S. S.; Jewitt, D. C.; "An Abundant Population of Small Irregular Satellites Around Jupiter" Archived August 13, 2006, at the Wayback Machine, Nature, Vol. 423 (May 2003), pp. 261–263
8. Nesvorný, D.; Alvarellos, J. L. A.; Dones, L.; and Levison, H. F.; "Orbital and Collisional Evolution of the Irregular Satellites", The Astronomical Journal, Vol. 126 (2003), pp. 398–429
9. Sheppard, S. S.; Jewitt, D. C.; Porco, C. C.; "Jupiter's Outer Satellites and Trojans" Archived June 14, 2007, at the Wayback Machine, in Jupiter: The Planet, Satellites and Magnetosphere, edited by Fran Bagenal, Timothy E. Dowling, and William B. McKinnon, Cambridge Planetary Science, Vol. 1, Cambridge, UK: Cambridge University Press, ISBN 0-521-81808-7, 2004, pp. 263–280
10. Grav, T.; Holman, M. J.; Gladman, B. J.; and Aksnes, K.; "Photometric survey of the irregular satellites", Icarus, Vol. 166 (2003), pp. 33–45

Further reading

• Ephemeris IAU-MPC NSES
• Mean orbital parameters NASA JPL