Reduced Light Curve: LP-filtered measurements, signal only, not normalized, 64 binned frames.



At the begining of the event the distance between Ganymede and Europe was only 8 pixels (between the centers) and only 3 pixels (between the edges of the centroids). The two graphs below show the background noise derived using two different methods.

In the first method below the noise is derived from the I0 value of the PSF fits:



The second method is based on a background value derived from an area between 3 and 5 FWHM away from the center of the satellite



Apertures used for the measurement:



Observation:

Using WAT120N+ on low gain; 1/4 sec exposure, no focal reducer, no Barlow



Prediction: