Listing of Poster Abstracts

Preliminary orbits and masses for the satellites of Pluto

Dr.  Marina Brozovic (JPL)

We report on the latest ephemerides (plu020) for the satellites of Pluto. The model for the satellites' orbits is numerical integration. External perturbations due to the Sun (augmented with the inner solar system planets), Jupiter, Saturn, Uranus, and Neptune are included. The data set consists of astrometric measurements and lightcurves from the mutual events and occultations. Our goal was not only to better constrain the satellites' orbits, but also to improve upon Pluto's orbit, as well as to provide the latest estimates for the GMs for the entire Pluto system. While Pluto and Charon GMs fit together with values from other sources, the formal errors indicate that the GMs of Nix and Hydra cannot be reliably obtained from the current data set with the assumed dynamical model.