Observed and modeled line profiles for spatially resolved positions across the disk of HD 209458. a) Observed profiles for stronger and weaker Fe I lines at average disk position μ = 0.86 (solid blue), compared to synthetic profiles (λ = 620 nm, χ = 3 eV) for differently strong lines at the same μ from a model of T_eff = 5900 K (dotted green). Same types of data in b) for μ = 0.78, c) for μ = 0.61, and d) for μ = 0.33 are shown. Synthetic full-disk profiles are shown in e), broadened for stellar rotation of 4 km s^-1, for the T_eff = 5900 K model (dotted green) and for 6250 K (dashed blue). A comparison to observed profiles outside transit (solid) confirms a stellar rotational velocity around such a value. All synthetic lines are here convolved with the spectrometer instrumental profile in f of FWHM = 4.0 km s^-1.