Prediction of stellar occultations by satellite of asteroids

Our group is working on the orbit determination of asteroid satellites on the last four years gathering data recorded with several AO systems. Based upon our observations, we focused specifically on models for (22) Kalliope, (121) Hermione, (45) Eugenia and (90) Antiope systems characterizing accurately their dynamical and physical properties (Marchis et al., 2003, 2004a, 2004b). These models will be regularly improved with new observations.

This work allow us to predict the position of the secondary during stellar occultations. A successful observation will give us direct measurements of the size and shape of the moonlet which is usually too small to be resolved by any available AO systems. These parameters are important to better constrain the mass of the system, its density, and consequently the internal structure of the primary.

We will predict the Earth track path of the secondary and primary events for the next years stellar occultations happening under good observing conditions and involving the satellites of (22) Kalliope, (121) Hermione, (45) Eugenia and the same-size binary asteroid (90) Antiope. A regularly updated web page http://stellarocc.imcce.fr/ contains the list of the events.

This work is supported by the National Science Foundation Science and Technology Center for Adaptive Optics, and is based partly on observations collected at the European Southern Observatory, Chile.