Left panels: Fourier periodogram of the decorrelated BRITE photometry of HD 149 404 in the frequency range 0 to 20 d⁻¹ (upper panel) and after pre-whitening of P_orb and P_orb/2 (middle panel). Semi-amplitudes are expressed in magnitudes. Lower panel: spectral window. Right panels: zoomed-in version of the frequency range between 0 and 1 d⁻¹. Upper, middle, and lower panels: Fourier periodogram, analysis of variance (AoV), and conditional entropy methods, respectively. In the Fourier and AoV method a detection of a signal corresponds to a peak, whereas in the conditional entropy method a detection is indicated by a minimum. The long- and short-dashed red lines correspond to ν_orb and 2 × ν_orb, respectively.