Io transiting jupiter's great red spot

Jupiter put on a nice show for west coast observers last weekend: Jupiter's moon Io and it's shadow transited the planet's surface just as the great red spot (GRS) was rotating into view.  

Io and shadow transiting Jupiter's great red spot
11/12/2023 06:45.8 UTC
CM1 331.7 CM2 46.6 CM3 86.7 CLat +3.8
Winjupos combination of 4x90 sec captures with independent processing of Io

The dark circle to the left of the great red spot is Io's shadow.  Io hovers over the top portion of the GRS. Close inspection of Io reveals detail on the jovian moon: dark patches top and bottom with a bright equatorial region.

Io and shadow transiting Jupiter's great red spot
11/12/2023 06:35.7 UTC
CM1 325.5 CM2 40.5 CM3 80.6 CLat +3.8

Animation of Io transit (larger version below):

Io and shadow transiting Jupiter's great red spot
11/12/2023 05:19-8:05 UTC

imaging details:
Eastbluff, CA
11/12/23 
still shot 06:35.7 UTC
CM1 325.5 CM2 40.5 CM3 80.6 CLat +3.8

winjupos shot 06:45.8 UTC

CM1 331.7 CM2 46.6 CM3 86.7 CLat +3.8
celestron 11" Edge HD
ZWO ASI 290MC (one shot color camera)
2x barlow
90 second captures at 5 minute intervals

05:19-08:05 UTC
FPS (avg.)=102
Shutter=2.976ms
Gain=351 (58%)
Histogramm=78%

animation scaled to 50%

i'm guessing capturing at higher histogram level facilitates detail on the jovian moons

software:
firecapture
autostakkert
winjupos (for CM measurement only)
registax
photoshop

started with poor seeing, which fortunately improved during the GRS transit

very dry so dew was not an issue

unfortunately, collimation was way off. wondering if i focused from the wrong direction, introducing mirror flop.  might be time for a crayford focuser.

on the plus side, it's rare for me to capture detail on a jovian moon, so a win despite poor collimation.  

PS full scale animation processed for frames with better seeing:

Io and shadow transiting Jupiter's great red spot
11/12/2023 05:19-8:05 UTC