Analysis of the residuals time series after planetary signals subtraction. Panel a: GLS periodogram of the residuals after subtracting the 18.3 d signal. A peak at ~89 d and another one at ~650 d are visible. Panel b: GLS periodogram of the residuals after subtracting the 18.3 d and 89.6 d signals. A peak at ~650 d is visible. Panel (c): GLS periodogram of the residuals after subtracting the 18.314, 650.9, and 89.65 d signals. We see some additional peaks in the periodogram of the residuals with FAP < 0.1% at periods of ~85 and 111 d.