Managed to get an 8 x 10minute exposures of NGC2070 last night for my Luminance channel.
Just playing around with the resultant set of pictures and ran DSS followed by StarTools.
Looking at the image, I notice a sort of 'rotation' and duplicated stars at the top near the middle. My thinking would be that DSS did not completely align the FITS files accurately enough causing duplicate stars that are just off from each other.
Yeah, I've had DSS do that once or twice. I've always assumed that the frames have been miss-read or not distinct enough for it to align. Seems to happen more when I attempt a second run at the same frames. No idea why although I have seen comment on earlier posts about it.