Instead of measuring the precise locations and total fluxes of the components of Mizar we see in the maps, we use these maps for initial guesses as to these parameters and improve these using the observed squared visiblities and phases.

Model fit

Begin by reading an already prepared model file for 1997-05-01.


This model has already best-fit parameter values set, but feel free to change them. The model is stored in variables star_model, binary_model .

Then use Model|FIT and Fit|INTERFEROMETRY to bring up the following widgets, and set the fields to match what you see. Some parts of these are clickable for further information.

Click on "Fit" in the (large) model fit widget. This will start a Marquardt-Levenberg non-linear least-squares fit. After this fit completes, click on "A-B" in the model fit widget to obtain the following listing of the parameters of the binary component. Of course, only the selected parameter values should have changed. The (rho,theta) result is entered into a file containing the results from all of the nights. It is used in the next section.

SEMIMAJORAXIS= 9.8400002 +/- 0.0000000
INCLINATION= 60.590000 +/- 0.0000000
ASCENDINGNODE= 106.10000 +/- 0.0000000
ECCENTRICITY= 0.53680003 +/- 0.0000000
PERIASTRON= 104.10000 +/- 0.0000000
APSIDALMOTION= 0.0000000 +/- 0.0000000
EPOCH= 7636.0600 +/- 0.0000000
PERIOD= 20.538370 +/- 0.0000000
RHO= 9.4227274 +/- 0.0023362788
THETA= 98.185225 +/- 0.027380840