Computed Fourier spectrum (top panel, black), the orbital frequency, and the first 47 orbital harmonics (top panel, dashed red lines) that cover the range of frequencies < 40 days⁻¹, above which no significant peaks are found. The bottom row shows the 3rd, 12th, and 25th orbital harmonics (dashed red lines) and the zoomed-in parts of the spectrum that correspond to these frequencies.