Hello astronomers!
I am currently working on a SHO Mosaic image in cygnus. Ha is already done, I am now moving to OIII.
This is one of the 4 OIII panels, and I am not really sure what this artefact on the bottom is. It could be from the star Sadr, which is in the panel below.
This artefact is only in this panel (in all of the sub frames), the other panels are fine. Thus, I rule out issues with flat frames.
Setup:
Telescope: Sharpstar 130HNT Newton
Camera: ZWO ASi 1600MM
Filter: Optolong OIII
Any ideas?

I am currently working on a SHO Mosaic image in cygnus. Ha is already done, I am now moving to OIII.
This is one of the 4 OIII panels, and I am not really sure what this artefact on the bottom is. It could be from the star Sadr, which is in the panel below.
This artefact is only in this panel (in all of the sub frames), the other panels are fine. Thus, I rule out issues with flat frames.
Setup:
Telescope: Sharpstar 130HNT Newton
Camera: ZWO ASi 1600MM
Filter: Optolong OIII
Any ideas?
