So what I did was write code to measure the position and brightness of Callisto over the course of the observing "night" (which was only over the couse of 20 minutes, 24 seconds).
Knowing the position of Callisto and the position of Jupiter, I can also compute the distance between them, which is shown in this first plot:
|Separation (in pixels) between Callisto & Jupiter|
(One thing I'll be doing on the next clear night is imaging a number of known visual binary stars to get a value of the pixel scale and field of view)
The next plot shows the photometry for Callisto over the same set of images and over the same timescale. I'm using aperture photometry with this and at the moment I'm using a 9x9 box centered on the computed centroid of the target. My aperture photometry computation will improve as I write better code (I eventually want fractional-pixel circular photometry). Here's the plot:
|Dark-subtracted aperture photometry of Callisto|
Again, I haven't done a numerical analysis of the photometric scatter, but it's on the order of 500 counts, which in this case is on the order of 5%. That's not good enough and I'm wondering why there is such a large scatter.
I'm also curious why the values seem to be changing over time. I wouldn't think that Callisto varies by that much (10%!!) over such a short period of time. There were high thin clouds in the area, so that might account for it. It's really hard to tell what's going on here. So at the moment I'll leave this and hope that I can better understand what's going on with more data.