Photometry with a periodic grid. II. Results for J2 Europa and S6 Titan

Abstract

The Hipparcos satellite successfully gathered astrometric and photometric information for a few solar system objects including natural satellites. In contrast to the case for asteroids, the Hipparcos main-mission does not provide the photometry - in the conventional sense - of planetary satellites. Nevertheless, valuable photometric results can be obtained, such as a modelling of the centre-to-limb darkening of the bodies. We present in this paper results obtained for the photometry with a periodic grid of the satellites J2 Europa and S6 Titan from the Hipparcos main mission and within the FAST data-reduction Consortium. The Minnaert parameter of S6 Titan is found to be k ~ 0.90+/-0.02, and for J2 Europa, k ~ 0.58+/-0.01. Brightness variations with orbital phase are also given for Europa.

Based on data from the Hipparcos astrometry satellite.