Generalized Lomb-Scargle periodograms of several activity indicators based on spectroscopic data obtained by CARMENES for HD 238090. The dashed black periodograms represent the GLS on the activity indicators, and the solid GLS periodogram represents the residuals from which a 365 d sinusoidal signal was subtracted. For the residuals from which the 365 d signal was subtracted, we also overplot the s-BGLS periodogram, where the probability increases from blue to white to red. The solid red lines mark the rotation period estimated by photometric data, and the dashed red lines show the 3σ uncertainties. The dashed black line marks a period of 365 d, and the dashed yellow line marks the period of the planetary signal published in this work.