Io transits Jupiter

This composite of Jupiter features a shadow transit of Io, with the moon itself visible as a yellowish disc just to the right of the dark round shadow. The image was made under good seeing conditions (7 in the 10-point scale by Pickering) and mostly transparent skies (4 in a 5-point scale).

Celestron Celestar 8 (200-millimeter) Schmidt-Cassegrain Telescope.
ZWO ASI224MC 1.2 MP Color CMOS Camera.
2x apochromatic Barlow lens.

7,000 frames processed with PIPP, AutoStakkert! and Registax 6.