Top: a close-up of the Fourier transform of KIC 11145123 (black) and the accepted oscillation periods (dashed red), showing the detected period spacings. The thick black markers indicate the frequencies that were extracted for α = 0.5. The amplitudes of some of the modes are ~3 mmag, but the figure is zoomed in for clarity. Bottom left: a close-up of the échelle diagram showing the detected prograde (squares), retrograde (circles) and zonal (triangles) dipole modes. The frequencies that were extracted with α = 0.5 are marked in black. Bottom right: the detected period spacings. For clarity, we shifted the spacings of the prograde and retrograde modes 150 s downwards and upwards, respectively.