Re: [PHOEBE-discuss] my problems with PHOEBE

[Andrej P. <ap...@vi...>]

> 1- how can I fitting without semi major axis in solar radii
> parameter? (I don't have any spectroscopy data)

You cannot solve a binary in absolute scale from photometry alone.
However, you can get relative sizes (R1/a, R2/a) from photometry. To do
that, set the semi-major axis to 1 and make sure you turn off logg
updates from the model (because these will, of course, not be correct
and phoebe uses them for limb darkening computations).

> 2- for light curve, I must to use magnitude of variable star or
> magnitude of variable star minus magnitude of comparsion star?
> because luminosities are correspond with magnitude. and with delta
> magnitude, I have overflow error and if I use magnitude of variable
> star so I've been دnot applying atmospheric corrections

You can use either; the transformation to fluxes (phoebe's intrinsic
unit) is done using the Zero Magnitude parameter (Data tab, bottom).
You should set that value to be close to your data. That will bring the
fluxes close to unity.

> 3- I have new error with fitting that I've attached it

I am not sure what exactly is going on here (Patrick might be able to
help better because it seems to be windows-related), but perhaps your
model is not close enough to describing the data properly to make DC
practical. Make sure that overplotting the model and the data result in
a reasonably close match before you start running DC.

Hope this helps,
Andrej