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S/2021 J 4
Discovery [1]
Discovered by Scott S. Sheppard
Discovery site Las Campanas Obs.
Discovery date14 August 2021
Orbital characteristics [1] [2]
Epoch 25 February 2023 ( JD 2460000.5)
Observation arc1.17 yr (427 d)
0.1533891  AU (22,946,680 km)
Eccentricity0.1585459
–1.94 yr (–710.13 days)
102.76481 °
0° 30m 25.027s / day
Inclination164.54657° (to ecliptic)
218.88401°
217.30730°
Satellite of Jupiter
Group Carme group
Physical characteristics
Mean diameter
1 km [3]
24.0 [3]
17.4 [1]

S/2021 J 4 is a small outer natural satellite of Jupiter discovered by Scott S. Sheppard on 14 August 2021, using the 6.5-meter Magellan-Baade Telescope at Las Campanas Observatory, Chile. It was announced by the Minor Planet Center on 19 January 2023, after observations were collected over a long enough time span to confirm the satellite's orbit. [1]

S/2021 J 4 is part of the Carme group, a tight cluster of retrograde irregular moons of Jupiter that follow similar orbits to Carme at semi-major axes between 22–24 million km (14–15 million mi), orbital eccentricities between 0.2 and 0.3, and inclinations between 163 and 166°. [3] It has a diameter of about 1 km (0.62 mi) for an absolute magnitude of 17.4, making it one of Jupiter's smallest known moons. [3]

References

  1. ^ a b c d "MPEC 2023-B40 : S/2021 J 4". Minor Planet Electronic Circulars. Minor Planet Center. 19 January 2023. Retrieved 20 January 2023.
  2. ^ "Planetary Satellite Discovery Circumstances". JPL Solar System Dynamics. NASA. Retrieved 10 January 2023.
  3. ^ a b c d Sheppard, Scott S. "Moons of Jupiter". Earth & Planets Laboratory. Carnegie Institution for Science. Retrieved 10 January 2023.