Author/Authors :
Kavelaars، نويسنده , , J.J. and Holman، نويسنده , , M.J. and Grav، نويسنده , , T. and Milisavljevic، نويسنده , , D. and Fraser، نويسنده , , W. and Gladman، نويسنده , , B.J. and Petit، نويسنده , , J.-M. and Rousselot، نويسنده , , P. and Mousis، نويسنده , , O. and Nicholson، نويسنده , , P.D.، نويسنده ,
Abstract :
We report the discovery of four new uranian irregular satellites in our deep, mR∼25.4, optical search around that planet. The orbital properties of these satellites are diverse. There is some grouping of inclinations and one of the satellites appears to be inside the Kozai resonant zone of Uranus. Further, we find that the differential size distribution of satellites is rather shallow compared to objects in the asteroid and Kuiper belts, going as ∼r−2.4. We also report a strong coupling between semi-major axis and orbital eccentricity. We comment on the apparent paradox between the inclination grouping, shallow size distribution, and orbital correlation as they relate to the likelihood of a collisional origin for the uranian irregulars. The currently observed irregulars appear to be consistent with a disruptive formation process and a collisional origin for Uranusʹ obliquity.
