Top panel: Lomb–Scargle periodogram of the RV residuals. There are multiple peaks above the 99% FAP (Power ∼ 0.06) but none of them corroborate with previous findings of the WASP-18 c (∼2.1 days). Middle panel: RV residuals fit with the periodogram Fourier model of 1.4065 days and a linear model. Both show similar BIC values. Bottom panel: RV residuals phase-folded at the highest detected peak of 1.4065 days.