On the stability of Saturns rings to gravity disturbances

Photometric and spectroscopic observations of Centaur Chiron have been obtained at the ESO/Very Large Telescope (VLT), both in optical and near-infrared spectral ranges, on 12-14 June 2001. Photometric optical data reveal that Chiron had reached a high activity level at that time. No absorption feature could be seen on the spectra; especially, no water ice could be detected.