PSD of six different simulated stars belonging to different classes (solar-like, β-Cephei, γ-Dor, RRLyrae, LPV, and Cepheid) as described by the y -axis labels of each panel. Coloured areas (red, grey, orange, and green) represent the different ranges of frequency used for the F_p, i calculation (from 0.7, 7, 20, and 50 μHz, respectively, to the Nyquist frequency). Coloured circles represent the class identifiers used in Fig. 2.