Paper detail

Eurybates - the only asteroid family among Trojans?

We study orbital and physical properties of Trojan asteroids of Jupiter. We try to discern all families previously discussed in literature, but we conclude there is only one significant family among Trojans, namely the cluster around asteroid (3548) Eurybates. It is the only cluster, which has all of the following characteristics: (i) it is clearly concentrated in the proper-element space; (ii) size-frequency distribution is different from background asteroids; (iii) we have a reasonable collisional/dynamical model of the family. Henceforth, we can consider it as a real collisional family. We also report a discovery of a possible family around the asteroid (4709) Ennomos, composed mostly of small asteroids. The asteroid (4709) Ennomos is known to have a very high albedo $p_V \simeq 0.15$, which may be related to a hypothetical cratering event which exposed ice (Fernández et al. 2003). The relation between the collisional family and the exposed surface of the parent body is a unique opportunity to study the physics of cratering events. However, more data are needed to confirm the existence of this family and its relationship with Ennomos.