Eupheme (moon)

Eupheme /juːˈfiːmiː/, also Jupiter LX, originally known as S/2003 J 3, is an outer natural satellite of Jupiter, 2 km in diameter.

Eupheme

Discovery
Discovered by	Scott S. Sheppard
Discovery date	2003
Designations
Designation	Jupiter LX
Pronunciation	/juːˈfiːmiː/[1]
Named after	Ευφήμη Eyphēmē
Alternative names	S/2003 J 3
Adjectives	Euphemean /juːfɪˈmiːən/[2]
Orbital characteristics [3]
Semi-major axis	21199710 km
Eccentricity	0.253
Orbital period	−627.8 days
Mean anomaly	168.7°
Inclination	148.0°
Longitude of ascending node	292.0°
Argument of perihelion	109.0°
Satellite of	Jupiter
Group	Ananke group
Physical characteristics
Mean diameter	2 km
Apparent magnitude	23.4

Discovery

It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003.[4][5] The moon was lost following its discovery in 2003.[6][7][8][9] It was recovered in 2017 and given its permanent designation that year.[10]

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.[11] 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.[12][13]

Orbit

Eupheme orbits Jupiter at an average distance of 19,622 Mm in 561.518 days, at an inclination of 146° to the ecliptic (146° to Jupiter's equator), in a retrograde direction and with an eccentricity of 0.2507. It belongs to the Ananke group, retrograde irregular moons that orbit Jupiter between 19.3 and 22.7 Gm, at inclinations of roughly 150°.

References

1. Noah Webster (1884) A Practical Dictionary of the English Language
2. James Petigru Carson (1920) Life, Letters and Speeches of James Louis Petigru, p. 318
3. S.S. Sheppard (2019), Moons of Jupiter, Carnegie Science, on line
4. Daniel W. E. Green (March 4, 2003). "IAUC 8087: Satellites of Jupiter". International Astronomical Union.
5. 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 March 4, 2003 (discovery and ephemeris)
6. Beatty, Kelly (April 4, 2012). "Outer-Planet Moons Found — and Lost". www.skyandtelescope.com. Sky & Telescope. Retrieved June 27, 2017.
7. Brozović, Marina; Jacobson, Robert A. (March 9, 2017). "The Orbits of Jupiter's Irregular Satellites". The Astronomical Journal. 153 (4): 147. Bibcode:2017AJ....153..147B. doi:10.3847/1538-3881/aa5e4d.
8. Jacobson, B.; Brozović, M.; Gladman, B.; Alexandersen, M.; Nicholson, P. D.; Veillet, C. (September 28, 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.
9. Sheppard, Scott S. (2017). "New Moons of Jupiter Announced in 2017". home.dtm.ciw.edu. Retrieved June 27, 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.
10. Sheppard, Scott S. (2017). "Jupiter's Known Satellites". home.dtm.ciw.edu. Archived from the original on March 18, 2015. Retrieved August 10, 2017.
11. "Planet and Satellite Names and Discoverers". USGS Astrogeology Science Center. Retrieved August 27, 2019.
12. "Naming Contest for Newly-discovered Moons of Jupiter". www.iau.org. Retrieved August 27, 2019.
13. "Public Contest Successfully Finds Names For Jupiter's New Moons". www.iau.org. Retrieved August 27, 2019.