No photometry stars in NSG

3 replies121 views
Christian Bennich avatar
Hi all

Does anyone have any pointers in regards to the warning: “No photometry stars found”
Never seen it before, and comparing frames I don’t see any apparent differences on the frames. 

Thank you.
Christian Bennich avatar
I posted my question over here as well : https://www.backyardastro.org/topic/3977-normalizescalegradient-script/page/13/#findComment-35359 . I'm hoping that John can help.

I will update this thread as well.
andrea tasselli avatar
Bit more details of the where's and how's would help immensely. As a hint: it does happen in areas poorly covered by photometric surveys, typically far galactic N pole.
Christian Bennich avatar
It turned out that I had missed a couple of bad frames, which messed up the photometry in NSG. 
Human error (read….my own fault :happy-1smile
Related discussions
Shifting primary mirror
Hi All I hope that you have some experience that can help me here. When I image low on the horizon, my stars are not good📷 image.png Near Zenith - same star. 📷 image.png Yesterday I realised that my Primary mirror shifted - and that most likely was t...
Mirror issues can affect star detection and photometry calibration.
Mar 6, 2026
Mysterious star trailing solved: a cautionary tale of fan vibration with a fan cooled (especially ZWO) camera.
Suddenly after no problems with star shapes, the next night out they were just terrible! Below I show a gif comparing two 2 hr stacks, one with the good stars, and the next with elongated stars. In this example the distortion was vertical. But later ...
Star quality problems may prevent photometry star identification.
Nov 18, 2025
What could cause this bizarre diffraction spike effect?
I was doing some testing tonight to get a target framed(it’s too windy to actually image tonight), when I noticed in my test shots, that the brights star, Ain, has a very bizarre appearance, with multiple spikes coming off in many directions. I have ...
Diffraction/optical issues could cause photometry star detection failures.
Dec 9, 2025