PALOMAR OBSERVATIONS OF THE R-IMPACT OF COMET SHOEMAKER-LEVY-9 .1. LIGHT CURVES

We present near-infrared observations from Palomar observatory of the impact of fragment R of comet Shoemaker-Levy 9 with Jupiter on 21 July 1994. Two instruments were used to image the event at 3.2 and 4.5 mic rons simultaneously. The lightcurves from these image sequences both s how two faint precursor flashes, a bright main peak, and several oscil lations over the following hour. We identify the precursor flashes wit h the entry of the bolide into Jupiter's upper atmosphere, and with th e post-impact ejecta plume rising above the planet's limb. The main pe ak is due to the re-entry of the collapsing plume into Jupiter's atmos phere and the resultant shock heating.