Eupheme (moon)
Images of Eupheme by the Canada-France-Hawaii Telescope in February 2003 | |
| Discovery | |
|---|---|
| Discovered by | Scott S. Sheppard |
| Discovery date | 2003 |
| Designations | |
Designation | Jupiter LX |
| Pronunciation | /juːˈfiːmiː/[1] |
Named after | Ευφήμη Eyphēmē |
| S/2003 J 3 | |
| Adjectives | Euphemean /juːfɪˈmiːən/[2] |
| Orbital characteristics[3] | |
| Epoch 2026-01-01 | |
| Periapsis | 12.7 million km |
| Apoapsis | 27.7 million km (2026-Jan-23)[4] |
| 20.2 million km | |
| Eccentricity | 0.371 |
| −587.7 days | |
Average orbital speed | 2.5 km/s |
| 164° | |
| Inclination | 148.0° |
| 325° | |
| 119° | |
| Satellite of | Jupiter |
| Group | Ananke group |
| Physical characteristics | |
| 2 km[5] | |
| 23.4[5] | |
Eupheme /juːˈfiːmiː/, also Jupiter LX, originally known as S/2003 J 3, is an outer irregular satellite of Jupiter, 2 km in diameter. It orbits Jupiter at an average distance of 20 million km, but gets as far away as 27.7 million km.[a]
Discovery
It was discovered by a team of astronomers from the University of Hawaiʻi led by Scott S. Sheppard in 2003.[6][7] The moon was lost following its discovery in 2003.[8][9][10][11] It was recovered in 2017 and given its permanent designation that year.[12]
Name
It was named in 2019 after Eupheme, the ancient Greek spirit of words of good omen, praise, acclaims, shouts of triumph, and applause, the daughter of Hephaestus and Aglaea and granddaughter of Zeus.[13] The name was suggested by Twitter user Lunartic (@iamalunartic) in a naming contest held by the Carnegie Institute on the social network who concurrently helped in naming another Jovian moon Philophrosyne.[14][15] The name ends in an "e" because the orbit is retrograde.
Orbit
Eupheme orbits Jupiter at an average distance of 20 million km in 588 days, at an inclination of 148° to the ecliptic, in a retrograde direction and with an eccentricity of 0.370.[3] It belongs to the Ananke group, retrograde irregular moons that orbit Jupiter between 19.3 and 22.7 million km, at inclinations of roughly 150°.
Eupheme next comes to apojove (farthest distance from Jupiter) on 23 January 2026 when it will be 0.185 AU (27.7 million km; 17.2 million mi) from Jupiter.[4]
Notes
References
- ^ Noah Webster (1884) A Practical Dictionary of the English Language
- ^ James Petigru Carson (1920) Life, Letters and Speeches of James Louis Petigru, p. 318
- ^ a b Horizons output. "Jovian Osculating Orbital Elements for Eupheme (560)". Retrieved 30 November 2025.
- ^ a b "Apojove on 2026-Jan-23". JPL Horizons. Retrieved 2 December 2025.
- ^ a b S.S. Sheppard (2019), Moons of Jupiter, Carnegie Science, on line
- ^ Daniel W. E. Green (4 March 2003). "IAUC 8087: Satellites of Jupiter". International Astronomical Union.
- ^ MPEC 2003-E11: S/2003 J 1, 2003 J 2, 2003 J 3, 2003 J 4, 2003 J 5, 2003 J 6, 2003 J 7 4 March 2003 (discovery and ephemeris)
- ^ Beatty, Kelly (4 April 2012). "Outer-Planet Moons Found — and Lost". www.skyandtelescope.com. Sky & Telescope. Retrieved 27 June 2017.
- ^ Brozović, Marina; Jacobson, Robert A. (9 March 2017). "The Orbits of Jupiter's Irregular Satellites". The Astronomical Journal. 153 (4): 147. Bibcode:2017AJ....153..147B. doi:10.3847/1538-3881/aa5e4d.
- ^ Jacobson, B.; Brozović, M.; Gladman, B.; Alexandersen, M.; Nicholson, P. D.; Veillet, C. (28 September 2012). "Irregular Satellites of the Outer Planets: Orbital Uncertainties and Astrometric Recoveries in 2009–2011". The Astronomical Journal. 144 (5): 132. Bibcode:2012AJ....144..132J. doi:10.1088/0004-6256/144/5/132. S2CID 123117568.
- ^ Sheppard, Scott S. (2017). "New Moons of Jupiter Announced in 2017". home.dtm.ciw.edu. Retrieved 27 June 2017.
We likely have all of the lost moons in our new observations from 2017, but to link them back to the remaining lost 2003 objects requires more observations a year later to confirm the linkages, which will not happen until early 2018. ... There are likely a few more new moons as well in our 2017 observations, but we need to reobserve them in 2018 to determine which of the discoveries are new and which are lost 2003 moons.
- ^ Sheppard, Scott S. (2017). "Jupiter's Known Satellites". home.dtm.ciw.edu. Archived from the original on 18 March 2015. Retrieved 10 August 2017.
- ^ "Planet and Satellite Names and Discoverers". USGS Astrogeology Science Center. Retrieved 27 August 2019.
- ^ "Naming Contest for Newly-discovered Moons of Jupiter". www.iau.org. Retrieved 27 August 2019.
- ^ "Public Contest Successfully Finds Names For Jupiter's New Moons". www.iau.org. Retrieved 27 August 2019.