[Aavso-photometry] Var Her 04 Update

[Arne Henden]

Looks like they will have to update their listing!

This was a difficult one to split.  The 1.0m never gets better
than 1.5-2.0arcsec seeing (long story), so I derived the positions
through a number of means.  First, in outburst, the B magnitudes
of the pair are dominated by the CV.  Then, near quiescence, the
H magnitudes are dominated by the red companion.  These give the
best astrometry for each star.  Finally, I went ahead and psf-fit
a large number of frames from the 1.0m to ensure that the coordinates
were roughly correct and the variable/redstar assignment was correct
(sanity checks).  I still haven't finished the photometric reductions
to get the magnitudes/colors for the red companion, but that analysis
is nearly complete.  I'm glad I don't have to do this very often!
   Bottom line, though, is that near quiescence you need to subtract
the contribution of the red companion from your photometry to obtain
results just for the CV.  You need to use a standard filter (tough
at 16th magnitude, I know) and something like Lew Cook's spreadsheet:
http://www.geocities.com/lcoo/nemesis.htm
Reporting combined light to the AAVSO is ok, but here is yet another
case where data entry software is not flexible enough.  You cannot
differentiate between posted photometry that is combined light or
subtracted light, except perhaps in the comments field.
Arne

bedient at hawaii.rr.com wrote:
> And interestingly enough, SIMBAD is already carrying Var Her 04 as
> EQ J183926+260409 -- Cataclysmic Variable Star .
> 
> Of course, their position is off by an arcsec in declination...  ;-)
> 
> Jim 
>