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 | |
Mean diameter | 9.6±1.3 km [6] |
Albedo | 0.052±0.016 [6] |
20.8 [7] | |
13.92±0.02 [6] | |
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]
It was named in October 2002 after Callirrhoe, daughter of the river god Achelous, one of Zeus's (Jupiter's) many conquests. [12]
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 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]
As a navigation exercise, the New Horizons spacecraft imaged Callirrhoe on January 10, 2007. [15]
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 | |
Mean diameter | 9.6±1.3 km [6] |
Albedo | 0.052±0.016 [6] |
20.8 [7] | |
13.92±0.02 [6] | |
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]
It was named in October 2002 after Callirrhoe, daughter of the river god Achelous, one of Zeus's (Jupiter's) many conquests. [12]
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 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]
As a navigation exercise, the New Horizons spacecraft imaged Callirrhoe on January 10, 2007. [15]