Took 56 2 minute images of the Flame Nebula last night and after processing, there was a unexpected oval green nebula like object in the upper right of the photo. It shows up mainly in green, but can be seen barely in L,B & R.
Thought it may have been related to the flat frames, so I took a new set of flats this afternoon, (rotated and cleaned the light box), and it is still there. It comes out in the digital development step at the end of the processing. Any ideas what it is?
The second image is not calibrated at all and shows the oval in the green channel.
I thought maybe it could be some reflection from Alnitak, but that is primarily in the blue range....
Any comments/Ideas would be appreciated! (I'm clouded over tonight, so can't re-image today, will try tomorrow)
12" RCX400 f6.3 fl=1229 ~f5, SBIG ST8XME, AO8, CFW9, 14 images each in L,R,G&B (120 seconds each) , taken this morning between midnight and 3:30AM MST 1/12/18
Edited by river157, 12 January 2018 - 08:57 PM.