The Dutch Observatory

November 14, 2009 on 2:53 am | In Jupiter, Planets | Comments Off

Tonight was another opportunity for a mutual event with the moons Ganymede and Io.  Ganymede would occult Io starting at 22:20 UT and complete the occultation at 22:46 UT.  Both moons were travelling in the same direction.  In addition, the images taken see a moon shadow beginning a transit of Jupiter around 22:59 UT   and another shadow leaving the disk at approx. 22:55.  The problem was that local sunset was at 22:32 UT.  So I would need to start imaging before the sun had set.  I used my binoculars to locate Jupiter, but it took me until a few minutes into the event to get things positioned right.  In addition, I had a problem with WinJupos showing the graphical info for this specific date, so I checked Sky and Telescope, but they showed Ganymede’s shadow start crossing the disk at 23:02  and Io’s shadow leaving the disk at 23:06.  So I am confused.  Sorry for the everexposure of Jupiter, and not being able to calibrate this better because of the light conditions when I started.  Here the result of this ”early” event.