The region of the Hα line for HD 261711: observed spectrum (black solid line), synthetic spectrum with the final adopted stellar parameters (T_eff = 8600 K, log g = 4.1 – red thick solid line) and synthetic spectra calculated by increasing/decreasing T_eff by 200 K (blue dashed lines). Note that the three synthetic spectra overlap because of the little reaction of the Hα line to T_eff  variations in this temperature regime.