Affiliation
American Association of Variable Star Observers (AAVSO)
Sun, 09/19/2021 - 15:25
I'm working on a sequence for NSV 16854 in MON using the field star 100 as check and 950 as comp.
After loading the sequence I see reasonable SNR on target, check and comp stars. So it looks good.
But when I view Photometry Report both target, comp and check stars show 0.000 mag with reasonable ERR. BUT: This only happens using R filter. B, V and I filters all report appropriate magnitudes.
Does this mean that not all AAVSO standard comp stars have B, V, R and I magnitudes??
Peter
Peter:
The quick answer is that although most AAVSO comps have mags for all filters (BVRI), there are exceptions related to the source catalog. Sometimes the R (or other) mag may not be provided.
You could confirm that the R mag is missing for the specific comp by checking out the sequence details.
Ken
PS: There are other reasons/errors for having 0.000 mag but check this first.
Changing Comp and Check stars fixed it.
Since all three stars showed 0.000 mag, is there any way to know upfront whether its the check or comp without known magnitude?
This is the 1st I'd seen that issue.
Thanks,
Peter
Hmm, I don't see comps 100 or 95 for this star on a 180 arc-minute chart.
Also, those comps are not on the list when I plot "Photometry" rather the "Chart".
I have B, Rc and Ic checked on the bottom of the request form.
Plotting to mag 12.5 .
Where did i get confused?
Ray