Lysithea (moon)


Lysithea in a 2MASS photograph
Discovery [1]
Discovered bySeth B. Nicholson
Discovery siteMt. Wilson Observatory
Discovery date6 July 1938
Jupiter X
Named after
Λυσιθέα Lysithea
AdjectivesLysithean /lˈsɪθiən/[4]
Orbital characteristics[5]
Epoch 27 April 2019 (JD 2458600.5)
Observation arc79.87 yr (29,171 days)
0.0782144 AU (11,700,710 km)
+258.57 d
1° 23m 32.227s / day
Inclination26.29254° (to ecliptic)
Satellite ofJupiter
GroupHimalia group
Physical characteristics
Mean diameter
42.2±0.7 km[6]
12.78±0.10 h[7]

Lysithea /lˈsɪθiə/ is a prograde irregular satellite of Jupiter. It was discovered by Seth Barnes Nicholson in 1938 at Mount Wilson Observatory[1] and is named after the mythological Lysithea, daughter of Oceanus and one of Zeus' lovers.[9]

Lysithea did not receive its present name until 1975; before then, it was simply known as Jupiter X. It was sometimes called "Demeter"[10] from 1955 to 1975.

It belongs to the Himalia group, five moons orbiting between 11 and 13 Gm from Jupiter at an inclination of about 28.3°.[11] Its orbital elements are as of January 2000. They are continuously changing due to solar and planetary perturbations.

Lysithea observed by the Wide-field Infrared Survey Explorer (WISE) spacecraft in 2014

See also


  1. ^ a b Nicholson, S. B. (October 1938). "Two New Satellites of Jupiter". Publications of the Astronomical Society of the Pacific. 50 (297): 292–293. Bibcode:1938PASP...50..292N. doi:10.1086/124963.
  2. ^ "Lysithea". Unabridged. Random House.
  3. ^ Cf. also 'Lysithous' in Noah Webster (1884) A Practical Dictionary of the English Language
  4. ^ Yenne (1987) The Atlas of the Solar System.
  5. ^ a b "M.P.C. 115890" (PDF). Minor Planet Circular. Minor Planet Center. 27 August 2019.
  6. ^ a b Grav, T.; Bauer, J. M.; Mainzer, A. K.; Masiero, J. R.; Nugent, C. R.; Cutri, R. M.; et al. (August 2015). "NEOWISE: Observations of the Irregular Satellites of Jupiter and Saturn" (PDF). The Astrophysical Journal. 809 (1): 9. Bibcode:2015ApJ...809....3G. doi:10.1088/0004-637X/809/1/3. S2CID 5834661. 3.
  7. ^ Luu, Jane (September 1991). "CCD photometry and spectroscopy of the outer Jovian satellites". Astronomical Journal. 102: 1213–1225. Bibcode:1991AJ....102.1213L. doi:10.1086/115949. ISSN 0004-6256.
  8. ^ Sheppard, Scott. "Scott S. Sheppard - Jupiter Moons". Department of Terrestrial Magnetism. Carnegie Institution for Science. Retrieved 26 November 2020.
  9. ^ Marsden, Brian G. (7 October 1975). "Satellites of Jupiter". International Astronomical Union.
  10. ^ Payne-Gaposchkin, Cecilia; Katherine Haramundanis (1970). Introduction to Astronomy. Englewood Cliffs, N.J.: Prentice-Hall. ISBN 0-13-478107-4.
  11. ^ Jacobson, R.A. (2000). "The orbits of outer Jovian satellites" (PDF). Astronomical Journal. 120 (5): 2679–2686. Bibcode:2000AJ....120.2679J. doi:10.1086/316817.

External links

  • Lysithea: Overview by NASA's Solar System Exploration
  • David Jewitt pages
  • Jupiter's Known Satellites (by Scott S. Sheppard)