Pre-whitened Fourier spectrum of the MOST light curve of HR 8799, after the subtraction of the 28 frequencies listed in Table 1. Dashed curves show the 4σ noise level. Vertical dashed lines in the bottom panel and in the “Window function” insert panel mark the multiples of the orbital frequency (f_orb = 14.2 d^-1) of MOST. Bottom panel: residual spectrum up to 100 d^-1; top panel: blow-up of the investigated frequency range.