Hi Alex,
That is an awesome result for an 8 inch scope.
The line you are getting is almost definately because one of
the frames in your stack went near or touched the edge of the
FOV. I get them quite often.
Quite a good feeling isn't it to keep getting your personal best
change in a few nights
?
I'm glad you took the advice to get the IR filter.
Focusing is sooooo much easier.
Keep them coming!.
Inspirational!
Steve B.