I noticed some of my stars are this donut shaped. This happens across two targets I tried. I have so far tried the following:
1. Re-run autofocus (though I am not sure if this is the issue since other stars are in focus)
2. Physically tighten up the imaging train so there is no unnoticed slack
I have uploaded my stacked image here:
I see this with the individual image frames as well (I also uploaded the individual sub to google drive).
Any idea what could be causing this?
80mm Doublet refractor, ASI533 OSC, ZWO Dualband filter, Auto Focus using ZWO EAF in NINA,
Polar alignment was within <1 arc second and PHD2 RMS error was ~0.6