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VSP and VPhot comp sequences differ

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spp
spp's picture
VSP and VPhot comp sequences differ

The AAVSO comp star sequence for V0742 Lyr (formerly NSV 11154) shown by VSP is different from the sequence used by VPhot.  The most obvious difference to me is that there are 3 comps stars with R and I photometry in the VSX sequence and only one comp star with this information in the AAVSO sequence used by VPhot.

I'll edit my saved VPhot sequence for this star using the information from the VSP table.  

Should we routinely  compare the two sequences before we start observing a new star?  I had assumed that when a comp sequence is updated VPhot would automatically use the new sequence.  Apparently, this is not always the case.

I have attached an I filtered FITS image of this star for testing.

Phil

spp
spp's picture
"never mind"

I figured out what was happening.  The two additional stars with R and I photometry didn't appear in my image, so they did not appear in the VPhot sequence table. 

My bad.

Phil

 

ka5sma
ka5sma's picture
VPHOT and VSX differ

I uploaded image of WZ Cep to VPHOT, got message could not do photometry because there was no AUID for this star?   WZ Cep does have a AUID in VSX ?

spp
spp's picture
WZ Cep

Yes, 000-BDL-193, and 6473 observations. 

Did you load the "Variable Star Index" from the Catalogs option box or mark it as a target by clicking on it?

SGEO
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WZ Cep issue

Mike,

I'm taking this question to Sebastian. I'm puzzled too why WZ Cep is not being offered back by the VSX call.

George

SGEO
SGEO's picture
WZ Cep issue

MIke, you come up with the most interesting problems! This is a strange one.

VPhot's request to VSX for variable star identification failed to include the WZ Cep variable because of an oddity in the FITS header of the file. CDELT1 and CDELT2 are negative. Never seen that before as these are scale results from the plate solving. Anyway, VPhot saw this and asked VSX for variables in a default 30' field of view rather than the images true 200'x100' fov. Thus WZ Cep was missed.

I adjusted your file and sure enough, the call to VSX was complete now.

Can't fix this in the code right now, but have added it to the VPhot todo list...

George

 

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