AAVSO report magnitudes

[Andrew C Murphy]

I'm having some issues with the output of an AAVSO report for a variable. I am using one check star and one comparison star for the report - not an ensemble, and not applying a transformation. The observations are made with a DLSR, using green channel (TG).

What I find is that the magnitudes of all three stars (variable, check, and comparison) in the AAVSO report, are different to the values shown in the main photometry screen. See attached.

Is there some transformation happening that I'm not aware of?

(The star shown as 143721.7-584739 is actually the recent Nova V1935 Cen)

[Andrew C Murphy]

Actually, I think I've got my head around what's happening here. The mag values in the photometry tab do make use of the Gaia comp stars (V05 database). So, when I don't use a GAIA ensemble in the AAVSO report, the variable magnitudes are naturally going to be a little different.

[han.k]

Yes, you could see the magnitudes in the photometry tab as the instrumental mangitudes. But one nearly correct using Gaia. In other program it could 20 magnitudes off.

So the photometry tab and graph are all in instrumental magnitudes which are almost correct using Gaia database as reference..
The report values are corrected with a small amount using the comparison star as reference.

cs Han