Callirrhoe (moon)

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Callirrhoe
S1999j1.jpg
Spacewatch image from 1999
Discovery[2]
Discovered by Spacewatch
Discovery site Kitt Peak National Observatory[1]
Discovery date Oct-Nov 1999
Designations
S/1999 J 1[2]
1999 UX18[2][3]
Orbital characteristics[4]
24,103,000 km
Eccentricity 0.2829
758.77 d (2.1 yr)
152.818°
Inclination 147.167°
89.00°
30.477°
Satellite of Jupiter
Physical characteristics
Dimensions ~8.6 km[5]
Albedo 0.04 (assumed)
20.7[5]

Callirrhoe (/kəˈlɪrɵʊ/ kə-LIRR-o-ee; Greek: Καλλιρρόη), also known as Jupiter XVII (17), is one of Jupiter's outermost named natural satellites. It is an irregular moon that orbits in a retrograde direction. Callirrhoe was imaged by Spacewatch at Kitt Peak National Observatory from October 6 through November 4, 1999,[1] and originally designated as asteroid (1999 UX18).[3][6] It was discovered to be in orbit around Jupiter by Tim Spahr on July 18, 2000, and then given the designation S/1999 J 1.[2][7] It was the 17th confirmed moon of Jupiter.[1]

Callirrhoe has an apparent magnitude of 20.7,[5] making it even fainter than dwarf planet Eris at magnitude 18.7.[8] Jupiter is about 2.5 billion times brighter than Callirrhoe.[9]

Callirrhoe is about 8.6 kilometers in diameter,[5] and orbits Jupiter at an average distance of 24.1 million kilometers in 758 days, at an inclination of 141° to the ecliptic (140° to Jupiter's equator) with an eccentricity of 0.28. This object was probably captured long ago from a heliocentric orbit and the Sun's gravitational influence makes this orbit highly erratic.[1]

It was named in October 2002 after Callirrhoe, daughter of the river god Achelous, one of Zeus' (Jupiter's) many conquests.[10]

It belongs to the Pasiphae group, irregular retrograde moons orbiting Jupiter at distances ranging between 22.8 and 24.1 million kilometers, and with inclinations ranging between 144.5° and 158.3°.

As a navigation exercise, the New Horizons spacecraft imaged it on January 10, 2007.[11]

References[edit]

  1. ^ a b c d "New Outer Satellite of Jupiter Discovered". Minor Planet Center. Retrieved 2009-07-23. 
  2. ^ a b c d Brian G. Marsden (2000-07-20). "IAUC 7460: S/1999 J 1". IAU. 
  3. ^ a b "New moon of Jupiter found". SpaceFlight Now (University of Arizona News Release). Retrieved 2009-07-23. 
  4. ^ Jacobson, R.A. (2006) JUP261 (2009-04-03). "Planetary Satellite Mean Orbital Parameters". JPL/NASA. Retrieved 2009-07-23. 
  5. ^ a b c d "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). 2009-04-03. Retrieved 2009-07-23. 
  6. ^ MPS 7418 (Minor Planet Circulars Supplement); not available on-line
  7. ^ MPEC 2000-Y16: S/1975 J 1 = S/2000 J 1, S/1999 J 1 2000-12-19 (discovery and ephemeris)
  8. ^ "AstDys (136199) Eris Ephemerides". Department of Mathematics, University of Pisa, Italy. Retrieved 2009-03-16. 
  9. ^ (5th root of 100)^(20.7-(-2.8))=2.51 billion
  10. ^ IAUC 7998: Satellites of Jupiter 2002 October 22 (naming the moon)
  11. ^ http://www.planetary.org/blogs/emily-lakdawalla/2007/jupiter_timeline.html

External links[edit]