SIngle frame of HH - double diffraction spikes.

[tooth_dr]

Hi all

I had a second night of crashing, where APT froze a few subs into the imaging run.  I'm currently running APT now with the same settings as last night to see if I can replicate the problem. So far it looks like the EFW is crashing and refusing to move, and this in turn affects everything on the same hub, then APT crashes.  Looks like a new EFW is needed

 

Anyway back to the main issue  - double diffraction spikes.  I ran SGPro last night and go the best fit focus position.  The thing is I dont think that the focuser has a small enough step.  I could be completely wrong, but IMHO it looks like focus is in between the two steps at the bottom of the curve.  Anything I can do to address this.  OR is it even a focus issue.  Tracking was good last night, RMS on each axis was 0.6 with total RMS of 0.8.  Exposure times were 300s, and this kept the ADUs between 1300 and 55000 (within the saturation limit of the QHY9 mono sensor).  The spikes are on all axis and parallel.  Scope is Epsilon 180.

 

Any opinions/advice grealy welcomed.  I've attached a single sub from this morning, unprocessed.

 

CS

Adam

 

Edited October 27, 2019 by tooth_dr

[tooth_dr]

Here is a stack from last night, SH2-155, and a screen shot of my guiding figures.  Do you think it looks a little out of focus, or what else is going on?  6 x 300s