Distributions of the noise amplitude in FTs of 200-day (left) and 1440-day (right) light curves. The simulated light-curve noise was set at the levels corresponding to ~13.6 ppm of the average FT noise (σ) for the 200-day and ~4.9 ppm for the 1440-day data sets. The FSB width was set to 0 μHz. The verticalblue lines at 10.6 and 3.7 ppm denote histogram maxima, while the average FT noise is indicated by the dashed lines.