The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin.
Their semi-major axes (distances from Jupiter) range between 22.7 and 23.6 Gm, their orbital inclinations between 164.4° and 164.9°, and their orbital eccentricities between 0.25 and 0.28 (with one exception).
The Carme group members are:[1] [2]
| Name | Diameter (km) | Period (days) | Notes | |
|---|---|---|---|---|
| 46 | –734.19 | largest member and group prototype | ||
| 5 | –732.45 | |||
| 4 | –723.71 | |||
| 5 | –742.02 | substantially redder than the others | ||
| 3 | –728.48 | |||
| 4 | –726.27 | |||
| 3 | –730.10 | |||
| 2 | –729.64 | |||
| 2 | –719.47 | |||
| 3 | –731.88 | |||
| 2 | –728.26 | |||
| 4 | –730.30 | |||
| 2 | –734.52 | |||
| 2 | –736.51 | |||
| 4 | –729.84 | |||
| 2 | –734.78 | |||
| 2 | –724.71 | |||
| 2 | –737.28 | |||
| 1 | –719.76 | |||
| 2 | –733.21 | |||
| 1 | –736.86 | |||
| 2 | –755.43 | |||
| 2 | –721.60 | |||
| 2 | –713.64 | |||
| 1 | –747.02 | |||
| 1 | –728.28 | |||
| 2 | –747.74 | |||
| 1 | –720.97 | |||
| 2 | –738.33 | |||
| 1 | –781.56 |
The International Astronomical Union (IAU) reserves names ending in -e for all retrograde moons.
The very low dispersion of the mean orbital elements among the core members (the group is separated by less than 900,000 km in semi major axis and only 0.5° in inclination) suggests that the Carme group may once have been a single body that was broken apart by an impact. The dispersion can be explained by a very small velocity impulse (5 < δV < 50 m/s).[3] The parent body was probably about the size of Carme, 46 km in diameter; 99% of the group's mass is still located in Carme.[4]
Further support to the single body origin comes from the known colours: all the satellites appear light red, with colour indices B-V= 0.76 and V-R= 0.47[5] and infrared spectra, similar to D-type asteroids.[6] These data are consistent with a progenitor from the Hilda family or a Jupiter trojan.