Praxidike (moon)

Praxidike /prækˈsɪdəkiː/, also known as Jupiter XXVII, is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2000,^[7][1] and given the temporary designation S/2000 J 7.

Praxidike

Praxidike imaged by the Canada-France-Hawaii Telescope in December 2001
Discovery[1]
Discovered by	Scott S. Sheppard et al.
Discovery site	Mauna Kea Obs.
Discovery date	23 November 2000
Designations
Designation	Jupiter XXVII
Pronunciation	/prækˈsɪdəkiː/[2]
Named after	Πραξιδίκη Praxidikē
Alternative names	S/2000 J 7
Adjectives	Praxidikean /ˌpræksədəˈkiːən/[3]
Orbital characteristics [4]
Semi-major axis	21147000 km
Eccentricity	0.230
Orbital period (sidereal)	−609.25 days[5]
Mean anomaly	21.8°
Inclination	149.0°
Longitude of ascending node	285.2°
Argument of perihelion	209.7°
Satellite of	Jupiter
Group	Ananke group
Physical characteristics
Mean diameter	7.0±0.7 km[6]
Albedo	0.029±0.006[6]
Apparent magnitude	21.2

It was named in August 2003 after Praxidike,^[8] the Greek goddess of punishment.

Orbit

Praxidike observed by the WISE spacecraft in 2010

Praxidike orbits Jupiter at an average distance of 20,824,000 km in 609.25 days, at an inclination of 144° to the ecliptic (143° to Jupiter's equator), in a retrograde direction and with an eccentricity of 0.1840.

Praxidike belongs to the Ananke group, believed to be the remnants of a break-up of a captured heliocentric asteroid.^[9][10] With an estimated diameter of 7 km, Praxidike is the second largest member of the group after Ananke itself (assumed albedo of 0.04).^[11]

Characteristics

The satellite appears grey (colour indices B-V=0.77, R-V= 0.34), typical of C-type asteroids.^[12]