Improvement of the ephemerides of Phoebe, 9th satellite of Saturn, from new observations made from 1995 to 2000

International audienceIn order to improve the model used for the ephemerides of Phoebe, the 9th satellite of Saturn, we started observations in 1998. We made 135 observations in 1998 and 39 observations in 1999 using the 120 cm-telescope of Observatoire de Haute-Provence, France. We used a numerical integration in order to calculate new initial conditions and to be able to build new ephemerides. We also used some precise observations made from 1995 to 2000 together with old observations for that purpose. The result is a decrease in the uncertainties on Phoebe's orbit