Observed (black line and dots) and modeled spectra of HD 189733 in four lines of Fe I with various Landé factors (see the g value in the line label). Three models are compared: a model spectrum with fixed spectroscopic parameters and a magnetic field fixed to zero (red line); a model with fitted spectroscopic parameters in which all lines contributing equally to the fit, even the broadened ones and no magnetic field (orange line), and a model in which all parameters are fit (blue line) (see text). The dashed line represents the spectrum that is not corrected for the telluric lines.