Affiliation
American Association of Variable Star Observers (AAVSO)
Tue, 12/07/2021 - 21:26
When I look at the VPhot Measurement Details window for some stars in some of my images, I sometimes find that the sky annulus mean is smaller than the sky annulus minimum. (Or maybe I'm misinterpreting what these numbers mean.) For example, in a recent image of the field around RZ Per:
Sky Annulus Statistics:
Mode:105.51
Mean:105.78
Median:106
Std.:8.85
Max:131
Min:109
Nbr. of Pixels904
What does the "Min" number represent?
- Mark M (MMU)
Good catch Mark.
Take a look at the section above, Signal Circle Statistics. That Min. value is the same as the Min. value reported in the Sky Annulus statistics.
Looks like a programming glitch. That has been there for 13 years! You are the first to report it!
I'll get this patched in the next VPhot update which I hope to have ready before the end of the year.
George