A new dynamical solution of (45) Eugenia's satellites

International audience(45) Eugenia and its satellites are one of the few triple asteroid systems discovered. Eugenia's shape is far from spherical, with a theoretical J2 estimated to 0.19 assuming an homogenous distribution of mass in its interiour. We have adapted the numerical model we developped for Pluto's system to Eugenia's case, adding the second harmonics of Eugenia's gravity field. Previous study by [4] found a lower value of the coefficient J2. We present here our results after fitting the satellites observations to our model using new observations of the system done in 2010 . We confirm that the value of J2 is about three times lower than its theoretical value. We find a similar pole direction for Eugenia and similar orbital elements for Petit-Prince