Synthetic data and their analysis. (a) The original OVRO observations are plotted as black filled circles. The synthetic data, containing the periods P₁ and P₂, are plotted as green filled squares. (b) Residuals (observed minus computed). (c) Histogram of the residuals. (d) GLS periodogram of the residuals, showing a significant peak at P_long. (e) Full GLS periodogram of the observational (black) and the synthetic data (green). The peak at P_long, present for the observational data, is missing for the synthetic data. The horizontal solid green line indicates the 0.1% FAP level of the synthetic data. (f) Zoom onto the orbital frequency range. The two periods, P₁ and P₂, are present for both the observational and the synthetic data. The nominal position of P₃ = 26.3 d is marked by the vertical dotted line. A feature is present at that position for both the observational and the synthetic data.