Astronomy:Callirrhoe (moon)

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Short description: Moon of Jupiter
Callirrhoe
S1999j1.jpg
This discovery image of Callirrhoe taken by Spacewatch in October 1999
Discovery [2]
Discovered bySpacewatch[lower-alpha 1]
Discovery siteKitt Peak National Observatory
Discovery date19 October 1999
Designations
Designation
Jupiter XVII
Pronunciation/kəˈlɪr/[3][4]
Named afterΚαλλιρρόη Kallirrhoê
S/1999 J 1
1999 UX18
Orbital characteristics[5]
Epoch 27 April 2019 (JD 2458600.5)
Observation arc17.54 yr (6,406 days)
0.1643278 astronomical unit|AU (24,583,090 km)
Eccentricity0.3095704
Orbital period–787.43 d
Mean anomaly240.90203°
Mean motion0° 27m 25.866s / day
Inclination147.99790° (to ecliptic)
Longitude of ascending node352.75480°
68.21981°
Satellite ofJupiter
GroupPasiphae group
Physical characteristics
Mean diameter9.6±1.3 km[6]
Albedo0.052±0.016[6]
Apparent magnitude20.8[7]
Absolute magnitude (H)13.9[5]


Callirrhoe (/kəˈlɪr./; Greek: Καλλιρρόη), also known as Jupiter XVII, is one of Jupiter's outer 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,[8] and originally designated as asteroid 1999 UX18.[9][10] 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][11] It was the 17th confirmed moon of Jupiter.[8]

Name

Stack of three images taken by the VLT in July 2000, showing Callirrhoe's movement relative to background stars

It was named in October 2002 after Callirrhoe, daughter of the river god Achelous, one of Zeus' (Jupiter's) many conquests.[12]

Characteristics

Callirrhoe has an apparent magnitude of 20.7,[13] making it even fainter than dwarf planet Eris at magnitude 18.7.[14] Jupiter is about 2.5 billion times brighter than Callirrhoe.[15]

Callirrhoe is about 9.6 kilometers in diameter,[6] and orbits Jupiter at an average distance of 24.1 million kilometers in 747.09 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.[8]

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°. However, while Pasiphae is gray (B−V=0.74, V−R=0.38, V−I=0.74) in color, Callirrhoe is light red (B−V=0.72, V−R=0.50, V−I=1.02) and more similar to Megaclite.[16]

Exploration

Callirrhoe imaged by the LORRI instrument aboard New Horizons

As a navigation exercise, the New Horizons spacecraft imaged Callirrhoe on January 10, 2007.[17]

Notes

  1. The discovery is credited to the team of astronomers consisting of J. V. Scotti, T. B. Spahr, R. S. McMillan, J. A. Larson, J. Montani, A. E. Gleason, and T. Gehrels.[1]

References

  1. "Planet and Satellite Names and Discoverers". Gazetteer of Planetary Nomenclature. USGS Astrogeology Science Center. https://planetarynames.wr.usgs.gov/Page/Planets#JovianSystem. Retrieved 26 November 2020. 
  2. 2.0 2.1 Brian G. Marsden (2000-07-20). "IAUC 7460: S/1999 J 1". IAU. http://www.cbat.eps.harvard.edu/iauc/07400/07460.html. 
  3. Noah Webster (1884) A Practical Dictionary of the English Language
  4. "Pasiphae". Dictionary.com Unabridged. Random House. https://www.dictionary.com/browse/Pasiphae. 
  5. 5.0 5.1 "M.P.C. 115890". Minor Planet Circular. Minor Planet Center. 27 August 2019. https://minorplanetcenter.net/iau/ECS/MPCArchive/2019/MPC_20190827.pdf. 
  6. 6.0 6.1 6.2 Grav, T.Expression error: Unrecognized word "etal". (August 2015). "NEOWISE: Observations of the Irregular Satellites of Jupiter and Saturn". The Astrophysical Journal 809 (1): 9. doi:10.1088/0004-637X/809/1/3. 3. Bibcode2015ApJ...809....3G. https://authors.library.caltech.edu/61254/1/Grav_2015.pdf. 
  7. Sheppard, Scott. "Scott S. Sheppard - Jupiter Moons". Department of Terrestrial Magnetism. Carnegie Institution for Science. https://sites.google.com/carnegiescience.edu/sheppard/moons/jupitermoons. Retrieved 26 November 2020. 
  8. 8.0 8.1 8.2 "New Outer Satellite of Jupiter Discovered". Minor Planet Center. https://minorplanetcenter.net//iau/pressinfo/S1999J1.html. Retrieved 2009-07-23. 
  9. "New moon of Jupiter found". SpaceFlight Now (University of Arizona News Release). http://spaceflightnow.com/news/n0007/21jovianmoon/. Retrieved 2009-07-23. 
  10. MPS 7418 (Minor Planet Circulars Supplement); not available on-line
  11. MPEC 2000-Y16: S/1975 J 1 = S/2000 J 1, S/1999 J 1 2000-12-19 (discovery and ephemeris)
  12. IAUC 7998: Satellites of Jupiter 2002 October 22 (naming the moon)
  13. "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). 2009-04-03. http://ssd.jpl.nasa.gov/?sat_phys_par. Retrieved 2009-07-23. 
  14. "AstDys (136199) Eris Ephemerides". Department of Mathematics, University of Pisa, Italy. https://newton.spacedys.com/astdys/index.php?pc=1.1.3.0&n=Eris. Retrieved 2009-03-16. 
  15. (5th root of 100)^(20.7-(-2.8))=2.51 billion
  16. Grav, Tommy; Holman, M. J.; Gladman, B. J.; Aksnes, K. (2003). "Photometric survey of the irregular satellites". Icarus 166 (1): 33–45. doi:10.1016/j.icarus.2003.07.005. Bibcode2003Icar..166...33G. 
  17. "New Horizons Jupiter Encounter Timeline". http://www.planetary.org/blogs/emily-lakdawalla/2007/jupiter_timeline.html. 

External links