Helike (moon)

Helike /ˈhɛləkiː/, also known as Jupiter XLV, is a moon of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003, and given the temporary designation S/2003 J 6.^[5][6][7]

Helike

Images of Helike by the Canada-France-Hawaii Telescope in February 2003
Discovery
Discovered by	Scott S. Sheppard et al.
Discovery date	2003
Designations
Designation	Jupiter XLV
Pronunciation	/ˈhɛləkiː/[1][2]
Named after	Ἑλίκη Helicē
Alternative names	S/2003 J 6
Adjectives	Helikean /hɛləˈkiːən/[3]
Orbital characteristics [4]
Semi-major axis	21263000 km
Eccentricity	0.156
Orbital period (sidereal)	−634.8 days
Mean anomaly	36.2°
Inclination	154.8°
Longitude of ascending node	100.3°
Argument of perihelion	314.7°
Satellite of	Jupiter
Group	Ananke group
Physical characteristics
Mean diameter	4 km
Apparent magnitude	22.6

Helike is about 4 kilometres in diameter, and orbits Jupiter at an average distance of 20.54 million kilometres in 601.402 days, at an inclination of 155° to the ecliptic (156° to Jupiter's equator), in a retrograde direction and with an eccentricity of 0.1375. Its average orbital speed is 2.48 km/s.

It was named in March 2005 after Helike, one of the nymphs that nurtured Zeus (Jupiter) in his infancy on Crete.^[8]

Helike belongs to the Ananke group.

References

1. "Helice". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
2. as 'Helice' in Noah Webster (1884) A Practical Dictionary of the English Language
3. Hutchinson (1980) "Base Metal Sulfides", The Continental Crust and Its Mineral Deposits: The Proceedings of a Symposium Held in Honour of J. Tuzo Wilson, Held at Toronto, May 1979, p. 679
4. S.S. Sheppard (2019), Moons of Jupiter, Carnegie Science, on line
5. Daniel W. E. Green (March 4, 2003). "IAUC 8087: Satellites of Jupiter". International Astronomical Union.
6. Brian G. Marsden (March 4, 2003). "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". International Astronomical Union Minor Planet Center.
7. Brian G. Marsden (March 7, 2003). "MPEC 2003-E29 : S/2003 J 9, 2003 J 10, 2003 J 11, 2003 J 12; S/2003 J 1, 2003 J 6". International Astronomical Union Minor Planet Center.
8. Daniel W. E. Green (March 30, 2005). "IAUC 8502: Satellites of Jupiter". International Astronomical Union.