Praxidike (moon)

Praxidike
Praxidike imaged by the Canada-France-Hawaii Telescope in December 2001
Discovery[1]
Discovered byScott S. Sheppard et al.
Discovery siteMauna Kea Observatory
Discovery date23 November 2000
Designations
Designation
Jupiter XXVII
Pronunciation/prækˈsɪdəkiː/[2]
Named after
Πραξιδίκη Praxidikē
S/2000 J 7
AdjectivesPraxidikean /ˌpræksədəˈkiːən/[3]
Orbital characteristics[4]
Observation arc25 years
2025-12-21 (last obs)[5]
21147000 km
Eccentricity0.230
−609.25 days[6]
21.8°
Inclination149.0°
285.2°
209.7°
Satellite ofJupiter
GroupAnanke group
Physical characteristics
7.0±0.7 km[7]
Albedo0.029±0.006[7]
Spectral type
C[8]
21,2
14.8 (119 obs)[5]

Praxidike /prækˈsɪdəkiː/, also known as Jupiter XXVII, is a small retrograde irregular satellite of Jupiter.

Discovery and Naming

It was discovered by a team of astronomers from the University of Hawaiʻi led by Scott S. Sheppard in 2000,[9][1] and given the temporary designation S/2000 J 7.

It was named in August 2003 after Praxidike,[10] the Greek goddess of punishment.

Orbit

Praxidike observed by the WISE spacecraft in 2010

Praxidike orbits Jupiter at an average distance of 21,147,000 km in 609.25 days, at an inclination of 149° to the ecliptic, in a retrograde direction and with an eccentricity of 0.230. Its orbit is continuously changing due to solar and planetary perturbations.

It belongs to the Ananke group, made up a tightly of irregular retrograde moons orbiting Jupiter at a distance ranging between 19–22 million km, inclinations between 144 and 156°, and eccentricities between 0.10 and 0.30.

Physical characteristics

With a diameter of 7 km, Praxidike is the second largest member of the group after Ananke itself. Based on infrared heat measurements taken by the WISE space telescope, Praxidike's albedo was measured at 2.9%, making it one of the least reflective bodies in our solar system. [7]

The satellite appears grey (colour indices B−V=0.77, R–V= 0.34), typical of C-type asteroids.[8]

Origin

Praxidike probably did not form near Jupiter but was captured by Jupiter later.Like the other members of the Ananke group, which have similar orbits, it is probably the remnant of a broken, captured heliocentric asteroid.

References

  1. ^ a b MPEC 2001-A29: S/2000 J 7, S/2000 J 8, S/2000 J 9, S/2000 J 10, S/2000 J 11 January 15, 2001 (discovery and ephemeris)
  2. ^ as 'Praxidice' in Noah Webster (1884) A Practical Dictionary of the English Language
  3. ^ There is also 'Praxidician' /præksəˈdɪʃiən/, as in the 'Praxidician goddesses' that include Praxidice, but this does not derive from the name Praxidice itself.
  4. ^ S.S. Sheppard (2019), Moons of Jupiter, Carnegie Science, on line
  5. ^ a b MPC Natural Satellites (Select: Orbital Elements)
  6. ^ "M.P.C. 104798" (PDF). Minor Planet Circular. Minor Planet Center. 10 May 2017.
  7. ^ a b c 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.
  8. ^ a b Grav, T.; Holman, M. J.; Gladman, B. J.; Aksnes, K.; Photometric Survey of the Irregular Satellites, Icarus, Volume 166 (2003), pages 33–45
  9. ^ IAUC 7555: Satellites of Jupiter January 5, 2001 (discovery)
  10. ^ IAUC 7998: Satellites of Jupiter 2002 October 22 (naming the moon)
This article is issued from Wikipedia. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.