Callirrhoe (moon)
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 2026-01-01 | |
| Observation arc | 17.54 yr (6,406 days) |
| Periapsis | 15.6 million km |
| Apoapsis | 30.9 million km |
| 23.3 million km | |
| Eccentricity | 0.329 |
| –724.4 days | |
| 322° | |
| 0° 27m 25.866s / day | |
| Inclination | 147.3° (to ecliptic) |
| 32.2° | |
| 102.2° | |
| Satellite of | Jupiter |
| Group | Pasiphae group |
| Physical characteristics | |
| 9.6±1.3 km[6] | |
| Albedo | 0.052±0.016[6] |
Spectral type | D[6] |
| 20.8[7] | |
| 13.92±0.02[6] | |
Callirrhoe (/kəˈlɪroʊ.iː/; Greek: Καλλιρρόη), also known as Jupiter XVII, is one of Jupiter's outermost natural satellites.
Discovery and Naming
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]
It was named in October 2002 after Callirrhoe, daughter of the river god Achelous, one of Zeus's (Jupiter's) many conquests.[12]
Orbit
Callirrhoe orbits Jupiter (at an average distance of 23.3 million km) on a high-eccentricity (0.33) and high-inclination (147° to ecliptic) retrograde orbit.[5] The orbital elements are continuously changing due to solar and planetary perturbations.
It belongs to the Pasiphae group, a group of retrograde moons jupiters with semi-major axes spread over 22–25 million km, inclinations between 141° and 158°, and higher eccentricities between 0.22 and 0.44.
Physical characteristics
Callirrhoe 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's measured albedo is around 5,2%, which means its diameter is 9,6 kilometers. [6]
While Pasiphae belongs to the grey color class (V=17.22 B−V=0.74, V−R=0.38), Callirrhoe falls under the light red color class (V=21.39 B−V=0.72, V−R=0.50), similarly to Megaclite and Sinope.[14]
Origin
Callirrhoe probably did not form near Jupiter but was captured by Jupiter later. Callirrhoe is believed to be a fragment from a captured asteroid along with other Pasiphae group satellites.[15][16]
However, it falls into a different color class than Pasiphae and could therefore have been captured by Jupiter independently of the Pasiphae group.
Exploration
As a navigation exercise, the New Horizons spacecraft imaged Callirrhoe on January 10, 2007.[17]
Notes
References
- ^ 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.
- ^ a b Horizons output. "Jovian Osculating Orbital Elements for Callirrhoe (517)". Retrieved 18 December 2025.
- ^ a b c d e 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 "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.
- ^ Brown, M. E. (2000). "Near-Infrared Spectroscopy of Centaurs and Irregular Satellites". The Astronomical Journal. 119 (2). The American Astronomical Society: 977–983. Bibcode:2000AJ....119..977B. CiteSeerX 10.1.1.22.1349. doi:10.1086/301202. S2CID 15143844.
- ^ Sheppard, S. S.; and Jewitt, D. C.; An Abundant Population of Small Irregular Satellites Around Jupiter Archived 5 August 2003 at the Wayback Machine, Nature, Vol. 423 (May 2003), pp. 261-263
- ^ "New Horizons Jupiter Encounter Timeline". www.planetary.org.
External links
- 17th Moon of Jupiter Discovered Archived 18 October 2019 at the Wayback Machine
- Spacewatch S/1999 J 1
- Spacewatch discovery picture