How to check the data
Both unfiltered CCD
measures and visual
estimates turn out to give
slightly
BRIGHTER
magnitudes than filtered
CCD data.
–
V = Visual + 0.14
–
V = Unfiltered V + 0.09
However, a typical difference
between CCD data and a
visual estimate of 0.1-0.2
magnitudes at magnitude 15
is not too bad…