Lysithea (moon)

Lysithea
Near-infrared photograph of Lysithea (center) by the 2MASS survey
Discovery [1]
Discovered bySeth B. Nicholson
Discovery siteMt. Wilson Observatory
Discovery date6 July 1938
Designations
Designation
Jupiter X
Pronunciation/laɪˈsɪθiə/[2][3]
Named after
Λυσιθέα Lysithea
AdjectivesLysithean /laɪˈsɪθiən/[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)
Eccentricity0.1478734
+258.57 d
27.18992°
1° 23m 32.227s / day
Inclination26.29254° (to ecliptic)
343.46495°
94.80010°
Satellite ofJupiter
GroupHimalia group
Physical characteristics
42.2±0.7 km (WISE)[6]
42.2±3 km (occultation)[7]: 6 
12.78±0.10 h[8]
Albedo0.036±0.006[6]
Spectral type
C/P[6]
18.2[9]
11.2[5]

Lysithea /laɪˈsɪθiə/ 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.[10]

Lysithea did not receive its present name until 1975; before then, it was simply known as Jupiter X. It was sometimes called "Demeter"[11] from 1955 to 1975.

It belongs to the Himalia group, moons orbiting between 11 and 13 Gm from Jupiter at an inclination of about 28.3°.[12] Its orbital elements are as of January 2000. They are continuously changing due to solar and planetary perturbations. It is gray in color (B−V=0.72, V−R=0.36, V−I=0.74) and intermediate between C-type and P-type asteroids.[13][6]

Lysithea observed by the Wide-field Infrared Survey Explorer (WISE) spacecraft in 2014
  1. ^ a b Cite error: The named reference Nicholson1938 was invoked but never defined (see the help page).
  2. ^ "Lysithea". Dictionary.com Unabridged (Online). n.d.
  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 Cite error: The named reference MPC115890 was invoked but never defined (see the help page).
  6. ^ a b c d Cite error: The named reference Grav2015 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference JOA2021-2 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Luu1991 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SheppardMoons was invoked but never defined (see the help page).
  10. ^ Marsden, Brian G. (7 October 1975). "Satellites of Jupiter". International Astronomical Union.
  11. ^ Payne-Gaposchkin, Cecilia; Katherine Haramundanis (1970). Introduction to Astronomy. Englewood Cliffs, N.J.: Prentice-Hall. ISBN 0-13-478107-4.
  12. ^ 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. S2CID 120372170.
  13. ^ Grav, Tommy; Holman, M. J.; Gladman, B. J.; Aksnes, K. (2003). "Photometric survey of the irregular satellites". Icarus. 166 (1): 33–45. arXiv:astro-ph/0301016. Bibcode:2003Icar..166...33G. doi:10.1016/j.icarus.2003.07.005. S2CID 7793999.