StarTools

I'm very new to AP and trying to figure out what's happened to Deneb here. My workflow was stacking in Syril then ST where I've just did a autodev, wipe, contrast and colour. The scope is a Redcat51 and camera is a Fuji XT1. I've also processed the image with Syril where the same thing happens so it's obviously not software related. I just don't know what it might be so any help will be much appreciated. The image is from near bottom right of the frame. Thanks, Roman.

Doh ... I didn't check my subs properly! 12 of the 80 had significant blue cast with a strong bloom around Deneb. Possibly an upstairs light being turned on somewhere and shining into the scope? Lesson learnt

Glad to hear you got that sorted. It can sometimes be caused by smoke or high/faint clouds as well.