I wondered why PX Dra was brightest in V.
This season I went looking for Gaia and found that comp 103 was a 40 mmag Gaia. The PX Dra light curve had ~ 40 mmag of noise on it. Deleting that comp made PX Dra brighter in I-band. Another season will tell if the 40 mmag of noise went away. I requested an AUID for Gaia DR3 1619736556503451520 .
Hi Ray,
it is brightest in V because the comparison star 103 actually varies between V= 10.53 and 10.56. Its APASS value used for the comparison star database is contaminated by PX Dra itself that it is 18" away but it is too bright so light coming from it is included in the fainter star measurement.
The different magnitudes in the plot do not make sense for an F-type star, the Ic and B can’t be that similar and V can’t be that brighter.
So remove this object as a comparison star, I have already done so.
Update the chart and use another comp and see what magnitudes you get.
I will ask the Sequence Team to find another comp star in the field.
I see that the 103 did not have Rc and Ic values in VSD, so you were using other comp stars for these bands?
Cheers,
Sebastian