[Aavso-photometry] BRI Comp Star Value when reporting OBS is the Chart V value?

[Tim Crawford]

Arne,

Are you saying that if we have a chart with a V
magnitude of say 10.0 that when we also REPORT BRI OBS
that we use 10.0 in the comp star field, provided that
BRI sequence data is available?

IF SO, me and a lot of other folks have been doing it
differently for a number of years.... makes me wonder
about how data will be looked at in the future if we
change horses in mid stream, so to speak.

In addition, some of us report the three decimals, if
available for comp values as that is how we measured
the photometry..... I would then suspect this might be
contrary to the New Policy, if such is in fact true,
of reporting just the V value from the Charts, which
usually only have one decimal.

This of course then raises the question of did the
observer use the three decimal sequence value or did
the observer use the rounded up Chart value when doing
the photometry?  

If we are only to report the Chart Value in ALL cases
when other color data is available (i.e., BRI) and
even though we have un-rounded up sequence data with
more decimals that we used for the photomety... then I
would hope you could get a special alert or something
out to this effect so that the word gets around.  

Thanks for the clarification, Boss... and if I read
your reply to Keith in error then I hope you and other
readers will chalk this email up to another senior
moment of the sender.

Also, I would hope that what ever changes are made or
suggestions as to how we respond in different
situations that the need to have to figure out a comp
code (not enough of 'em to deal with CCD issues) and
then enter a comment be kept TO A MINIMUM.

Tim Crawford CTX
Arch Cape Observatory


--- arne <arne at aavso.org> wrote:

> Enter the chart mag - that is the label that we use
> to ensure we know
> which comp star you were using.  We know what its
> BVRI magnitudes
> are from the calibration.  The exception to this is
> if there is
> no filter information for a given comp star.  Then
> give its label
> in the compstar field, but place in the comments
> what magnitude you
> assumed for that star.
> Arne
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