[Aavso-photometry] Re2: [AAVSO-DIS] I and R sequence for GW Lib?

[arne]

FIDRICH Robert wrote:
>>We've given the UBV catalog values for the 9.2mag field star earlier.
> 
> 
> 9.2 mag field star? 
> is this labelled as 94 comp star on the AAVSO (e) chart?
> 
> 
>>So basically, this star is pretty colorless.  I'd assume
>>Rc = 9.20 and Ic = 9.20 and report your data that way for the time
>>being, and be sure you put these assumed values in your comment field.
> 
> 
> If it is the "94" comparison on the visulas observers' chart we can use
> it since if is visible on our photos.
> 
> Otherwise we'll waiting for the SRO photometry.
> 
> For us it is not so urgent. We can submit the result to the AAVSO and
> HAA/VSS later...
> 
Yes, this is the 94 comp star.  I posted on 4/16/2007 to both
aavso-discussion and aavso-photometry a fairly
lengthy discussion of this star.

Richard Miles has just calibrated it at Ic.  Therefore,
for HD136234 (GSC/TYC 06766-01577), I think we can use
the following values for data submission:

U  9.74
B  9.50
V  9.20
Rc 9.02  (estimate)
Ic 8.85

with errors in the 0.02mag range, so I think good enough for
the time being.  If you submit data using these values, place
"Henden 20070419" in the comment field.

It remains non-photometric at SRO.  We are also getting UBVRcIc
datasets from another telescope, so should be able to calibrate
the 9-12mag range pretty shortly so that you have comp stars as
the CV fades.  As Richard mentions, the 107 and 123 sequence stars
are quite red, but this is a pretty sparse field and there may not
be any better choices.
Arne