Eirene (moon) explained

Eirene
Adjective:	Eirenean
Named After:	Εἰρήνη Eirēnē
Discoverer:	Scott Sheppard et al.
Discovered:	2003
Mpc Name:	Jupiter LVII
Alt Names:	S/2003 J 5
Orbit Ref:	 ^[1]
Inclination:	162.713° (to the ecliptic)
Eccentricity:	0.2413
Period:	−743.88 days (2.038 years)
Satellite Of:	Jupiter
Group:	Carme group
Magnitude:	22.5
Abs Magnitude:	15.8
Mean Diameter:	4 km

Eirene, also Jupiter LVII and originally known as , is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003^{[2] [3]} but was then lost.^{[4] [5] [6] [7]} It was recovered in 2017 and given its permanent designation that year.^[8]

Characteristics

Eirene is about 4 kilometres in diameter, and orbits Jupiter at an average distance of 23,974,000 km in 743.88 days, at an inclination of 166° to the ecliptic (167° to Jupiter's equator), in a retrograde direction and with an eccentricity of 0.307.

It belongs to the Carme group, made up of irregular retrograde moons orbiting Jupiter at a distance ranging between 23 and 24 Gm and at an inclination of about 165°.

Name

The moon was named in 2019 after Eirene (Εἰρήνη), the daughter of Zeus and Themis and the goddess of peace in Greek mythology; the name originated from a naming contest held on Twitter with sixteen tweets suggesting the name, most significantly by users Quadrupoltensor (@Quadrupoltensor) who first suggested the name and PaulR (@PJRYYC).^{[9] [10] [11]}

Notes and References

1. https://sites.google.com/carnegiescience.edu/sheppard/moons/jupitermoons S.S. Sheppard (2019), Moons of Jupiter, Carnegie Science, on line
2. http://cbat.eps.harvard.edu/iauc/08000/08087.html IAUC 8087: Satellites of Jupiter
3. https://www.minorplanetcenter.net/mpec/K03/K03E11.html 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. Web site: Outer-Planet Moons Found — and Lost . Beatty . Kelly . 4 April 2012 . www.skyandtelescope.com . Sky & Telescope . 27 June 2017.
5. Brozović . Marina . Jacobson . Robert A. . 9 March 2017 . The Orbits of Jupiter's Irregular Satellites . The Astronomical Journal . 153 . 4 . 147 . 10.3847/1538-3881/aa5e4d. 2017AJ....153..147B . free .
6. Jacobson . B. . Brozović . M. . B. . Gladman . M. . Alexandersen . P. D. . Nicholson . C. . Veillet . 28 September 2012 . Irregular Satellites of the Outer Planets: Orbital Uncertainties and Astrometric Recoveries in 2009–2011 . The Astronomical Journal . 144 . 5 . 132 . 10.1088/0004-6256/144/5/132 . 2012AJ....144..132J . 123117568 . free .
7. Web site: New Moons of Jupiter Announced in 2017 . Sheppard . Scott S. . 2017 . home.dtm.ciw.edu . 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..
8. Web site: Jupiter's Known Satellites . Sheppard . Scott S. . 2017 . home.dtm.ciw.edu . 10 August 2017 . https://web.archive.org/web/20150318034833/http://home.dtm.ciw.edu/users/sheppard/satellites/jupsatdata.html . 18 March 2015 . dead .
9. Web site: Planetary Names: Planet and Satellite Names and Discoverers.
10. Web site: Naming Contest for Newly-discovered Moons of Jupiter . www.iau.org . 27 August 2019.
11. Web site: Public Contest Successfully Finds Names For Jupiter's New Moons . www.iau.org . 27 August 2019.