Callirrhoe (/kəˈlɪroʊ.iː/; 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.[1][11] It was the 17th confirmed moon of Jupiter.[8]
 This discovery image of Callirrhoe taken by Spacewatch in October 1999 | |
| Discovery[1] | |
|---|---|
| Discovered by | Spacewatch[a] |
| Discovery site | Kitt Peak National Observatory |
| Discovery date | 19 October 1999 |
| Designations | |
Designation | Jupiter XVII |
| Pronunciation | /kəˈlɪroʊiː/[3][4] |
Named after | Καλλιρρόη Kallirrhoê |
| S/1999 J 1 1999 UX18 | |
| Orbital characteristics[5] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Observation arc | 17.54 yr (6,406 days) |
| 0.1643278 AU (24,583,090 km) | |
| Eccentricity | 0.3095704 |
| –787.43 d | |
| 240.90203° | |
| 0° 27m 25.866s / day | |
| Inclination | 147.99790° (to ecliptic) |
| 352.75480° | |
| 68.21981° | |
| Satellite of | Jupiter |
| Group | Pasiphae group |
| Physical characteristics | |
| 9.6±1.3 km[6] | |
| Albedo | 0.052±0.016[6] |
| 20.8[7] | |
| 13.92±0.02[6] | |
Name
editIt was named in October 2002 after Callirrhoe, daughter of the river god Achelous, one of Zeus's (Jupiter's) many conquests.[12]
Characteristics
editCallirrhoe has an apparent magnitude of 20.8,[7] making it even fainter than dwarf planet Eris at magnitude 18.7.[13] Jupiter is about 2.1 billion times brighter than Callirrhoe.[b]
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.[14]
Exploration
editAs a navigation exercise, the New Horizons spacecraft imaged Callirrhoe on January 10, 2007.[15]
Notes
editReferences
edit- ^ a b Brian G. Marsden (20 July 2000). "IAUC 7460: S/1999 J 1". IAU. Archived from the original on 26 April 2006. Retrieved 22 November 2005.
- ^ "Planet and Satellite Names and Discoverers". Gazetteer of Planetary Nomenclature. USGS Astrogeology Science Center. Retrieved 26 November 2020.
- ^ Noah Webster (1884). A Practical Dictionary of the English Language.
- ^ "Pasiphae". Dictionary.com Unabridged (Online). n.d.
- ^ "M.P.C. 115890" (PDF). Minor Planet Circular. Minor Planet Center. 27 August 2019.
- ^ a b c d 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.
- ^ a b Sheppard, Scott. "Scott S. Sheppard - Jupiter Moons". Department of Terrestrial Magnetism. Carnegie Institution for Science. Retrieved 26 November 2020.
- ^ a b c "New Outer Satellite of Jupiter Discovered". Minor Planet Center. Retrieved 23 July 2009.
- ^ "New moon of Jupiter found". SpaceFlight Now (University of Arizona News Release). Retrieved 23 July 2009.
- ^ MPS 7418 (Minor Planet Circulars Supplement); not available on-line
- ^ MPEC 2000-Y16: S/1975 J 1 = S/2000 J 1, S/1999 J 1 2000-12-19 (discovery and ephemeris)
- ^ IAUC 7998: Satellites of Jupiter 2002 October 22 (naming the moon)
- ^ "AstDys (136199) Eris Ephemerides". Department of Mathematics, University of Pisa, Italy. Retrieved 16 March 2009.
- ^ 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.
- ^ "New Horizons Jupiter Encounter Timeline". www.planetary.org.
External links
edit- 17th Moon of Jupiter Discovered Archived 18 October 2019 at the Wayback Machine
- Spacewatch S/1999 J 1
- Spacewatch discovery picture