I have looked to the images. The big stars are not a problem for detection but the number of hot pixels due to the uncooled ASI120. You can see that if you load the images in the ASTAP directly and use the CCD inspector option (in viewer, menu Tools, CCD inspector). Normally one pixel stars are ignored but due to the noise some are seen as stars.
- NGC2175 image solves if I reduce the maximum number of stars to 80 and tolerance to 0.009. This removes the hot pixels
- M33 solves
- NGC281, fails due to oval stars.
The solving will improve a lot if you use a dark. This is an option in ASTAP but rarely used and also a good opportunity to test now.
First make a few darks with about the same exposure time. Or make several e.g 5 of 10 sec, 20 sec, 40 seconds
To set and test this option in ASTAP:
1) Start ASTAP from the education topic menu
2) Load an existing image in ASTAP e.g. NGC 2175_Light_40_secs_001.fits using the viewer menu, FILE, LOAD FITS OR OTHER FORMAT.
3) Open the stack menu CTRL+A and set the red marked options including "Calibrate prior to solving" in the tab ALIGNMENT:
4) Add the darks to the tab DARKS. If you have with more then one exposure time, then activated option classify on DARK EXPOSURE. In this last case the darks should have exactly the same exposure time as an image otherwise they are ignored. If not leave this option unchecked and ASTAP will use any dark.
5) Then hit the SOLVE button in tab alignment or in the viewer. The settings will be saved. Solving should work better now. ASTAP will remember the settings and dark(s) if called from EKOS.
Could you share a dark so I can test it here?
Regards, Han