[Aavso-photometry] What Mags to Use?

[Brian D. Warner]

I did some CCD (V filter) work on U GEM last night. The chart magnitudes are good 
only to 0.1 precision. This seems a waste when working CCD, especially since the 
field has some higher precision values from Arne's work.

When I asked for the photometry on the chart, there were no magnitudes other than the 
labels, that 0.1 mag precision. I would have thought for this field that better 
(higher precision) magnitudes would have been listed.

So, can I use the Henden photometry from his most recent U GEM file on the AAVSO 
site, or should I stick with the lower precision values?

I'm working V432 PER tonight. The VSP provides a nice plot but no magnitudes. There 
are some stars from Brian Skiff's LONEOS catalog in the field, however. Is it OK to 
use those magnitudes (given to 0.01 precision)? If so, do I use his catalog 
designation since there are no AUID values for stars in the chart?

These are two specific examples, but maybe they can serve to provide some general 
answers, e.g., when working a field with no magnitudes at all or with magnitudes from 
another, reasonably calibrated source.


Clear Skies,
Brian D. Warner
Palmer Divide Observatory/Space Science Institute
http://www.MinorPlanetObserver.com

Collaborative Asteroid Lightcurve Link (CALL)
http://www.MinorPlanetObserver.com/astlc/default.htm