On January 29th four bright Jupiter’s moons grouped together East of Jupiter for a spectacular show, during which observers could see the transit of Io and the Great Red Spot (GRS).
An over-exposed image shows the planet and for bright moons; below is a stack of some 600 frames, which shows only the planet and three of it’s moons – Callisto is almost invisible due to insufficient dynamic range of the camera.
Lower row of the images displays the GRS and Io transits as they progressed. An interesting point is that bright Io can be seen only in the first two images, then at some point Io became invisible through the telescope, but Io’s shadow is clearly seen on the Jupiter’s atmosphere.

Equipment:
TAL-200K telescope, 200 mm f/10;  motorized EQ mount
Canon-EOS-550D DSLR
Between 600 and 800 frames were used for final stacks
Processed in Registax and Photoshop