Albiorix is the largest of the four known members of the Gallic group of moons, which orbit Saturn at a mean distance of 16 to 19 million km, at inclinations between 35 and 40 degrees from the plane of Saturn's equator, and with eccentricities around 0.53. (A satellite's eccentricity is a number between 0 and 1 which describes the shape of the orbit. The closer to 0, the more circular it is; the closer to 1, the more elongated.)
The Gallic moons all have prograde orbits (they travel around Saturn in the same direction as the planet's rotation), but their deviations from circular orbits and from the plane of Saturn's equator classify them as "irregular" satellites. Like Saturn's other irregular moons, they are thought to be objects that were captured by Saturn's gravity, rather than having accreted from the dusty disk that surrounded the newly formed planet, as the regular satellites are thought to have done.
The similarities among the orbits of moons in the Gallic group suggest a common origin -- they may be fragments of a single object that shattered in a collision. The other members of this group are Bebhionn, Erriapus and Tarvos.
Observations by Tommy Grav and James Bauer using telescopes on Mauna Kea, Hawaii in 2006 found that the color of Albiorix varies over its surface. They hypothesize that Tarvos and Erriapus, which were both seen to be light red, are the largest fragments from an impact on Albiorix, leaving a less-red crater. (These observations did not include Bebhionn.)
Albiorix has a mean radius of about 16 km, assuming an albedo of 0.06. At a mean distance of 16.4 million km from Saturn, the satellite takes about 784 Earth days to complete one orbit.
Discovery:
Albiorix was discovered on 9 November 2000 by Matthew J. Holman and Timothy B. Spahr, using the 6.5-m reflector telescope at the Fred Lawrence Whipple Observatory on Mt. Hopkins, near Amado, Ariz.
How Albiorix Got its Name:
Originally called S/2000 S11, Albiorix was named for a Gallic deity who may have been equivalent to the Roman god Mars.
