Himalia group

This diagram compares the orbital elements and relative sizes of the largest four members of the Himalia group. The horizontal axis illustrates their average distance from Jupiter, the vertical axis their orbital inclination, and the circles their relative sizes.
This diagram illustrates all the irregular satellites of Jupiter. The Himalia group is bunched together near the top of the diagram. An object's position on the horizontal axis indicates its distance from Jupiter. The vertical axis indicates its inclination. Eccentricity is indicated by yellow bars illustrating the object's maximum and minimum distances from Jupiter. Circles illustrate an object's size in comparison to the others.

The Himalia group is a group of prograde irregular satellites of Jupiter that follow similar orbits to Himalia and are thought to have a common origin.[1]

The known members of the group are (in order of increasing distance from Jupiter):

Name Diameter
(km)		 Period
(days)		 Notes
Leda 21.5 240.93
Ersa 3 249.23
Himalia 139.6
(150 × 120)		 250.56 largest member and group prototype
S/2018 J 2 3 250.88
Pandia 3 251.91
Lysithea 42.2 259.20
Elara 79.9 259.64
S/2011 J 3 3 261.77
Dia 4 278.21

Two additional possible satellites discovered by Sheppard in 2017 have been identified to be likely part of the Himalia group, but were too faint (mag >24) to be tracked and confirmed as satellites.[2]

The International Astronomical Union (IAU) reserves names for moons of Jupiter ending in -a (Leda, Himalia and so on) for the moons in this group to indicate prograde motions of these bodies relative to Jupiter, their gravitationally central object.[3]

  1. ^ Scott S. Sheppard, David C. Jewitt An abundant population of small irregular satellites around Jupiter, Nature, 423 (May 2003), pp.261-263 (pdf) Archived 2006-08-13 at the Wayback Machine
  2. ^ Sheppard, Scott; Williams, Gareth; Tholen, David; Trujillo, Chadwick; Brozovic, Marina; Thirouin, Audrey; et al. (August 2018). "New Jupiter Satellites and Moon-Moon Collisions". Research Notes of the American Astronomical Society. 2 (3): 155. arXiv:1809.00700. Bibcode:2018RNAAS...2..155S. doi:10.3847/2515-5172/aadd15. S2CID 55052745. 155.
  3. ^ Antonietta Barucci, M. (2008). "Irregular Satellites of the Giant Planets" (PDF). In M. Antonietta Barucci; Hermann Boehnhardt; Dale P. Cruikshank; Alessandro Morbidelli (eds.). The Solar System Beyond Neptune. University of Arizona Press. p. 414. ISBN 9780816527557. Archived from the original (PDF) on 10 August 2017. Retrieved 22 July 2017.