So imaging IC 348 in Ha for a few nights last week and stacked them PI and noticed this giant ring in the center. I stacked it in DSS without flats and still the same. I then stacked just different nights and it was still there. I thought about redoing some new flats and or cleaning the sensor of the ASI1600, however, on the last night I also move to NGC 1893 and got 30 min of that. NGC 183 showed no signs of the mysterious ring. Any ideas what happened. I have attached unprocessed (other than cropping) for review. I have never imaged IC 348 in Ha before, maybe the ring is real - it just looked too circular.