These asteroids are loose aggregations of rock presumably created when another asteroid smacked into it and disrupted it. A new asteroid formed later by accumulation of large fragments. The moonlets are probably debris left over from the collision that were captured by the newly formed asteroid and eventually settled into orbits around it. Because of the way they form, we expect to see more multiple asteroid systems like this.
French team:
- Pascal Descamps, Institut de Mécanique Céleste et de Calcul des Ephéméides, Observatoire de Paris
- Daniel Hestroffer, Institut de Mécanique Céleste et de Calcul des Ephémérides, Observatoire de Paris
- Jérôme Berthier, Institut de Mécanique Céleste et de Calcul des Ephémérides, Observatoire de Paris
American team:
- Franck Marchis, University of California at Berkeley, Department of Astronomy