Detection limits of the RV residuals (after correcting for a trend and long-term modulation) of the combined RVs of GJ 1151 of 20 HARPS-N, 25 HPF, and 70 CARMENES observations. We show the minimum planetary mass for which we detect (bootstrap false-alarm probability < 0.1%) an injected planetary companion for each period (black line). Coloured lines show constant semi-amplitudes of 1.25, 1.75 m s⁻¹ (blue lines), and the average detection limit of 1.50 m s⁻¹ (red line).