Hi and welcome to the forums!
@almcl has already given you great advice;
The circular green "glow" is not glow but is caused by uneven lighting (aka "vignetting"). You need to take flats and to compensate for the uneven lighting. Not only will that take care of uneven lighting, it will also take care of dust on your sensor (some small dust specks can be seen). Flats are really not optional.
Using the Vignetting preset in the Wipe module will work well if the vignetting is mostly centred and gradually falls off (crop the iamge first).
In this dataset, however, I can see some rather clear signs of "banding" (rather abrupt changes from one brightness level to another with no pixels in the image using the brightness levels in between). These abrupt changes make processing harder for most algorithms (as abrupt changes normally correlate with detail that needs preserving).Some things that may help;
- Can you tell us what stacking method you used? If you have 390 lights, you can use more sophisticated stacking algorithms (e.g. kappa-sigma). Banding may happen if you are using median stacking and/or if the signal in your RAW frames sits in just a few brightness levels with the rest allocated to gradients and light pollution.
- A good rule of thumb when shooting, is to make sure the background sky brightness level (usually the peak in your histogram) sits around 1/3rd from the left. This leaves 2/3rds of your sensor's dynamic range to encode "interesting detail".
- Shoot at an ISO that is native to your sensor. (see if you can find your camera here)
I managed this, processing your dataset;
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- 3-1.jpg (193.65 KiB) Viewed 3917 times
You captured the flame nebula (and very, very, very faint horsehead) in the bottom left as well.
I can post the processing log if you wish, but it mostly deals with working around the defects in your data, so I don't think it will be very re-usable.
Clear skies!
