Dia (moon)

Dia /ˈdaɪ.ə/, also known as Jupiter LIII, is a prograde irregular satellite of Jupiter. Provisionally known as S/2000 J 11, it received its name on March 7, 2015.^[3] It is named after Dia, daughter of Deioneus (or Eioneus), wife of Ixion. According to Homer, she was seduced by Zeus in stallion form; Pirithous was the issue.

Dia

Discovery
Discovered by	Scott S. Sheppard, David C. Jewitt, Yanga R. Fernández, and Eugene A. Magnier
Discovery site	Mauna Kea Obs.
Discovery date	5 December 2000 11 September 2012 (rediscovery)
Designations
Designation	Jupiter LIII
Pronunciation	/ˈdaɪ.ə/[1]
Named after	Δῖα Dīa
Alternative names	S/2000 J 11
Adjectives	Dian /ˈdaɪ.ən/
Orbital characteristics [2]
Semi-major axis	12118000 km
Eccentricity	0.211
Orbital period (sidereal)	+287.0 days
Mean anomaly	169.9°
Inclination	28.23°
Longitude of ascending node	290.9°
Argument of perihelion	178.0°
Satellite of	Jupiter
Group	Himalia group
Physical characteristics
Mean diameter	4 km
Apparent magnitude	22.4

The satellite is one of several known small bodies in the Himalia group.^[4]

Dia is thought to be about 4 kilometres in diameter.^[5] It orbits Jupiter at an average distance of 12 million km in 274 days, at an inclination of 28° (to Jupiter's equator), and with an eccentricity of 0.21.^[6]

Observational history

Dia imaged by the Canada-France-Hawaii Telescope in December 2001. In the second frame Dia is not visible due to Jupiter's glare reducing the relative brightnesses of the stars.

Dia was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2000 with an observation arc of 26 days.^[7][8]

Initial observations were not followed up, and Dia was not observed for more than a decade after 2000. This apparent disappearance led some astronomers to consider the moon lost.^[9] One theory was that it had crashed into Himalia, creating a faint ring around Jupiter.^[10] However, it was finally recovered in observations made in 2010 and 2011.^[6]

References

1. Noah Webster (1884) A Practical Dictionary of the English Language
2. S.S. Sheppard (2019), Moons of Jupiter, Carnegie Science, on line
3. CBET (Central Bureau Electronic Telegram) 4075: 20150307: Satellites of Jupiter, March 7, 2015
4. Sheppard, S. S.; Jewitt, D. C.; An abundant population of small irregular satellites around Jupiter Archived August 13, 2006, at the Wayback Machine, Nature, 423 (May 2003), pp. 261–263
5. Sheppard, S. S.; Jewitt, D. C.; Porco, C.; Jupiter's outer satellites and Trojans Archived June 14, 2007, at the Wayback Machine, in Jupiter: The planet, satellites and magnetosphere, edited by Fran Bagenal, Timothy E. Dowling, William B. McKinnon, Cambridge Planetary Science, Vol. 1, Cambridge, UK: Cambridge University Press, ISBN 0-521-81808-7, 2004, pp. 263-280
6. Williams, Gareth V. (September 11, 2012). "MPEC 2012-R22 : S/2000 J 11". Minor Planet Center. Retrieved September 11, 2012.
7. Daniel W. E. Green (January 5, 2001). "IAUC 7555: Satellites of Jupiter". International Astronomical Union.
8. Brian G. Marsden (January 15, 2001). "MPEC 2001-A29: S/2000 J 7, S/2000 J 8, S/2000 J 9, S/2000 J 10, S/2000 J 11". International Astronomical Union Minor Planet Center.
9. "FAQ: Why don't you have Jovian satellite S/2000 J11 in your system?". JPL Solar System Dynamics. Retrieved February 13, 2011.
10. "Lunar marriage may have given Jupiter a ring", New Scientist, March 20, 2010, p. 16.(subscription required)

External links

• Natural Satellites Ephemeris Service Minor Planet Center
• Planetary Satellite Mean Orbital Parameters NASA JPL
• Scott Sheppard pages
• David Jewitt pages