Transmission light curves (TLC) of HD 189733 b for all three nights combined using three different central bandwidths: 0.75 Å (left column), 1.50 Å (middle column) and 3.00 Å (right column). The gray data points show the relative absorption for each exposure; in black the data are binned by 20 spectra. The green background marks the exposures taken out-of-transit. First row: observed TLCs; the red dashed line shows the CLV and RM model. Second row: TLCs after removing the contribution of the CLV and RM effects.