  he triple asteroidal system (87) Sylvia is composed of a 280-km primary and
two small moonlets named Romulus and Remus (Marchis et al 2005). Sylvia is
located in the main asteroid belt. The satellites are in nearly equatorial
circular orbits around the primary. In the present work we study the stability
of the satellites Romulus and Remus, in order to identify the effects and the
contribution of each perturber. The results from the 3-body problem,
Sylvia-Romulus-Remus, show no significant variation of their orbital elements.
However, the inclinations of the satellites present a long period evolution,
when the Sun is included in the system. Such amplitude is amplified when
Jupiter is included. An analysis of these results show that Romulus and Remus
are librating in a secular resonance and their longitude of the nodes are
locked to each other. The satellites get caught in an evection resonance with
Jupiter. However, the orbital evolutions of the satellites became completely
stable when the oblateness of Sylvia is included in the simulations.
