Astronomy:Megaclite
 Megaclite imaged by the Canada-France-Hawaii Telescope in December 2001 | |
| Discovery[1] | |
|---|---|
| Discovered by | Scott S. Sheppard David C. Jewitt Yanga R. Fernandez Eugene A. Magnier |
| Discovery site | Mauna Kea Observatory |
| Discovery date | 25 November 2000 |
| Designations | |
Designation | Jupiter XIX |
| Pronunciation | /mɛɡəˈklaɪtiː/ |
| Named after | Μεγακλειτή Megaclītē |
| S/2000 J 8 | |
| Adjectives | Megaclitean /ˌmɛɡəklɪˈtiːən/ |
| Orbital characteristics[2] | |
| Epoch 2026-01-01 | |
| Observation arc | 16.26 yr (5,938 days) |
| |{{{apsis}}}|apsis}} | 13.1 million km |
| |{{{apsis}}}|apsis}} | 33.80 million km |
| 23.5 million km | |
| Eccentricity | 0.440 |
| Orbital period | –734.6 days |
| Mean anomaly | 256° |
| Mean motion | 0° 28m 54.732s / day |
| Inclination | 147.7° (to ecliptic) |
| Longitude of ascending node | 22.8° |
| 32.4° | |
| Satellite of | Jupiter |
| Group | Pasiphae group |
| Physical characteristics[5] | |
| Mean diameter | ≈ 6 km |
| Albedo | 0.04 (assumed) |
| Apparent magnitude | 21.7[3] |
| Absolute magnitude (H) | 15.0[4] |
Megaclite /mɛɡəˈklaɪtiː/, also known as Jupiter XIX, is one of Jupiter's smallest and outermost natural satellites.
Discovery and Naming
It was discovered by a team of astronomers from the University of Hawaiʻi led by Scott S. Sheppard in 2000, and given the temporary designation S/2000 J 8.[6][1][7]
It was named in October 2002 after Megaclite, mother by Zeus (Jupiter) of Thebe and Locrus in Greek mythology. It was initially erroneously named Magaclite, which was corrected in November 2002.[8][9] Despite this correction, some earlier research still referred to the moon as Magaclite.[10]
Orbit
Megaclite orbits Jupiter (on average at 23.5 million km) on a high-eccentricity (0.440) and high-inclination (148° to ecliptic) retrograde orbit. The orbital elements are continuously changing due to solar and planetary perturbations.
It belongs to the Pasiphae group, a group of retrograde moons of Jupiter 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
Megaclite's estimated diameter is 6 kilometers, assuming an albedo of 4%.
While Pasiphae belongs to the grey color class (B−V=0.74, V−R=0.38), Megaclite falls under the light red color class (B−V=0.94, V−R=0.41 ), similarly to Callirrhoe and Sinope.[10]
Origin
Megaclite probably did not form near Jupiter but was captured by Jupiter later. Megaclite is believed to be a fragment from a captured asteroid along with other Pasiphae group satellites.[11][12]
However, it falls into a different color class than Pasiphae and could therefore have been captured by Jupiter independently of the Pasiphae group.
References
- ↑ 1.0 1.1 MPEC 2001-A29: S/2000 J 7, S/2000 J 8, S/2000 J 9, S/2000 J 10, S/2000 J 11 2001 January 15 (discovery and ephemeris)
- ↑ Horizons output. "Jovian Osculating Orbital Elements for Megaclite (519)". https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%27Megaclite%27&TABLE_TYPE=%27ELEMENTS%27&START_TIME=%272026-01-01%27&STOP_TIME=%272026-01-02%27&STEP_SIZE=%271%20year%27&CENTER=%27@599%27&OUT_UNITS=%27KM-D%27.
- ↑ Sheppard, Scott. "Scott S. Sheppard - Jupiter Moons". Department of Terrestrial Magnetism. Carnegie Institution for Science. https://sites.google.com/carnegiescience.edu/sheppard/moons/jupitermoons.
- ↑ "M.P.C. 115890". Minor Planet Circular. Minor Planet Center. 27 August 2019. https://minorplanetcenter.net/iau/ECS/MPCArchive/2019/MPC_20190827.pdf.
- ↑ "Planetary Satellite Physical Parameters". Jet Propulsion Laboratory. 19 February 2015. https://ssd.jpl.nasa.gov/?sat_phys_par#jupiter.
- ↑ IAUC 7555: Satellites of Jupiter 2001 January 5 (discovery)
- ↑ MPEC 2001-T59: S/2000 J 8, S/2000 J 9, S/2000 J 10 2001 October 15 (revised ephemeris)
- ↑ IAUC 7998: Satellites of Jupiter 2002 October 22 (naming the moon "Magaclite")
- ↑ IAUC 8023: Satellites of Jupiter 2002 November 29 (correcting the name)
- ↑ 10.0 10.1 Grav, Tommy; Holman, M. J.; Gladman, B. J.; Aksnes, K. (2003). "Photometric survey of the irregular satellites". Icarus 166 (1): 33–45. doi:10.1016/j.icarus.2003.07.005. Bibcode: 2003Icar..166...33G.
- ↑ Brown, M. E. (2000). "Near-Infrared Spectroscopy of Centaurs and Irregular Satellites". The Astronomical Journal (The American Astronomical Society) 119 (2): 977–983. doi:10.1086/301202. Bibcode: 2000AJ....119..977B.
- ↑ Sheppard, S. S.; and Jewitt, D. C.; An Abundant Population of Small Irregular Satellites Around Jupiter , Nature, Vol. 423 (May 2003), pp. 261-263
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