Moon shadow of Jupiter drifting in WINJUPOS.

[WilliamAstro]

I have this problem where when I de-rotate an image of Jupiter with it's moon shadow (edging near the end) The final result ends up with the shadow being in a black line rather than being a black circle.

Cheers for any advice

William

[CraigT82]

Yeah shadow transits are a pain to deal with when derotating, and so are the moons themselves but to a lesser extent. This is due to the orbital velocity of the moons being different to the rotational velocity of Jupiter. 
 

I’m not aware of any workaround other than performing a cosmetic fix in post (I.e. copy a section of the planet’s disc with the shadow from a single stack and paste it into the correct location on the derotated image, or something like that).
 

Hopefully someone might be able to offer a better workaround, I’d be very interested to learn too.

Edited July 10, 2022 by CraigT82