Hermippe (moon)

Hermippe /hɜːrˈmɪpiː/, or Jupiter XXX, is a natural satellite of Jupiter. It was discovered concurrently with Eurydome by a team of astronomers from the Institute for Astronomy of the University of Hawaii led by David Jewitt and Scott S. Sheppard and Jan Kleyna in 2001, and given the temporary designation S/2001 J 3.[6][1]

Hermippe

Discovery image of Hermippe by the Canada-France-Hawaii Telescope in December 2001
Discovery [1]
Discovered by	Scott S. Sheppard David C. Jewitt Yanga R. Fernandez
Discovery site	Mauna Kea Observatory
Discovery date	9 December 2001
Designations
Designation	Jupiter XXX
Pronunciation	/hɜːrˈmɪpiː/[2]
Named after	Ἑρμίππη Hermippē
Alternative names	S/2001 J 3
Adjectives	Hermippean /hɜːrmɪˈpiːən/
Orbital characteristics [3]
Epoch 17 December 2020 (JD 2459200.5)
Observation arc	15.29 yr (5,586 days)
Semi-major axis	0.1381428 AU (20,665,870 km)
Eccentricity	0.1982520
Orbital period	–606.93 d
Mean anomaly	169.67605°
Mean motion	0° 35^m 35.347^s / day
Inclination	146.76001° (to ecliptic)
Longitude of ascending node	37.24213°
Argument of perihelion	356.27211°
Satellite of	Jupiter
Group	Ananke group
Physical characteristics[4]
Mean diameter	4 km
Albedo	0.04 (assumed)
Apparent magnitude	22.1[5]
Absolute magnitude (H)	15.5[3]

Hermippe is about 4 kilometres in diameter, and orbits Jupiter at an average distance of 21,500,000 kilometers in about 630 days, at an inclination of 151° to the ecliptic (149° to Jupiter's equator), in a retrograde direction and with an eccentricity of 0.2290.

It was named in August 2003 by the IAU, after Hermippe, a lover of Zeus (Jupiter).[7]

Hermippe belongs to the Ananke group, retrograde irregular moons which orbit Jupiter between 19.3 and 22.7 gigametres (0.152 astronomical units), at inclinations of roughly 150°.

Discovery image of Hermippe and Eurydome together taken in December 2001

References

1. MPEC 2002-J54: Eleven New Satellites of Jupiter May 15, 2002 (discovery and ephemeris)
2. cf. Hermippus in Noah Webster (1884) A Practical Dictionary of the English Language
3. "M.P.C. 127087" (PDF). Minor Planet Circular. Minor Planet Center. 17 November 2020.
4. "Planetary Satellite Physical Parameters". Jet Propulsion Laboratory. 19 February 2015. Retrieved 26 November 2020.
5. Sheppard, Scott. "Scott S. Sheppard - Jupiter Moons". Department of Terrestrial Magnetism. Carnegie Institution for Science. Retrieved 26 November 2020.
6. IAUC 7900: Satellites of Jupiter May 16, 2002 (discovery)
7. IAUC 8177: Satellites of Jupiter, Saturn, Uranus Archived 2008-07-09 at the Wayback Machine 2003 August (naming the moon)

External links

• Jupiter's Known Satellites (by Scott S. Sheppard)
• New Jupiter Satellite Movie Images (image)
• Astronomers Discover 11 More Small Moons of Jupiter (JPL, 2002)