Power spectra of the five target stars, with the spectrum of one of them, KIC 8461659, shown twice in the upper panels: one version (upper-left) which extends to low frequencies, and one version (upper-right) focussing on the frequency region of the oscillations. The effect of the filtering in the preparation of the light curve can be seen in the leftmost version of these, where the power drops off at low frequencies. We only show the version focused on the oscillations for the remaining four stars. The frequency of maximum power, ν_max, is indicated in each panel as a (red) vertical dashed line. The filled circles indicate the position of the 4–5 dominating ℓ = 0-modes near ν_max. Due to the stochastic nature of the oscillations, each mode is represented by a series of close peaks, which is the reason why the detailed frequency analysis is performed using smoothed versions of the power spectra (see text).