A SEARCH FOR VARIATIONS IN THE LIGHT CURVES OF IO AND EUROPA DURING THE IMPACT OF COMET SL9 - A-EVENT, H-EVENT, AND Q-EVENT

We observed Europa (A event) and lo (H and Q events) with a high speed photometer at the 0.6m telescope at Castel Gandolfo. Italy, to search for impact light echoes. Although several fluctuations in light level from these moons were detected, most can be attributed to terrestrial effects. However, some signals during all three events cannot be easi ly diagnosed as spurious, and may represent real flashes. In particula r, we see possible light echoes (at roughly the 2-sigma level) for the A, Q2 and Q1 events; an increase in signal from lo during the brighte st part of the H event as seen from Earth; and a three-sigma event fou r minutes after the Q2 event that matches a similar event observed in Kiev.