Fourier spectrum of the residuals of the LC model of WASP-167 from Sectors 10, 37, and 64 (left, middle, and right panel). The plots in the insets show the spectral windows. The dashed red line marks the second orbital harmonic of WASP-167b, demonstrating the critical frequency that influences primarily the mass measurements of the planet. The noise level, as calculated by Period04, is shown as a solid red line.