PHYSICAL-PROPERTIES OF THE AEROSOL DEBRIS GENERATED BY THE IMPACT OF FRAGMENT-H OF COMET-P SHOEMAKER-LEVY-9 ON JUPITER

The physical properties of the aerosol debris coming from the impact o f fragment H of comet P/Shoemaker-Levy on Jupiter are analyzed. Based on a high spatial resolution image set obtained at the 4.2m William He rschel Telescope at La Palms (Spain), we derived detailed limb darkeni ng curves at three wavelengths (3600, 8920 and 9480 Angstrom), which w e used to retrieve the aerosol physical properties and spatial distrib ution in the central core region of the impact site. We derived these properties combining the observations at two dates, that corresponding to the night of July 18th, 1994, just after the impact time, and that of July 21st; 1994. Radiative transfer models in combination with a M ie scattering program were used to retrieve the possible values of aer osol properties and spatial distribution compatible with these observa tions. The main results of the model computations are that the particl es are rather dark, with imaginary refractive indexes varying between 0.02 at 3600 Angstrom and 0.006 in the 9000 Angstrom region, have a me an radius of about 0.15 mu m, and are distributed between 1 and 450 mb ar with a total column concentration of 8.2x10(9) cm(-2), giving a tot al optical thickness of 3.6 at 9480 Angstrom. A lower limit to the vol ume of the impact debris aerosol is estimated to be that corresponding to a sphere of about 230 m in diameter.