this is noise it will occure when seeing and or transparence isnt good
you are picking noise from light thin clouds or high humidity in the atmosphere

mark

MTSO

If this image contains quite a few stacked images and the mount polar alignement causes drift between images stacked, dust particles on the camera lens or on the image sensor/IR filter if using a DSI, can causes these streaks to appear. The fact that the streaks seems to be at about 45 degress angle in the image would support this theory. You could try to verify if when using fewer stacked images the streaks are shorter to confirm this theory. In which case the only two possible solution I can think of is carefully and gently cleaning the optics and/or use flat field compensation to reduce the effects of the dust particles.

Claude