Stacked-Bayesian GLS periodogram of Lalande 21185. The color bar to the left color-codes each observation with the associated spectrograph (orange: CARMENES, and teal: SOPHIE). Left: s-BGLS of the zero-planet model at the period of theplanetary signal. Middle: s-BGLS on the residuals of the one-planet fit with a period of 12.95 d shown around a period of 55 d, which is the rotational period determined by Díaz et al. (2019). Right: s-BGLS on the residuals of the one-planet fit around the observed long-period signal.