Left panel: transit light curve folded to the orbital period of K2-141 b and residuals. The red points mark the K2 data, whereas the thick black line the re-binned best-fitting transit model. Right panel: phase-folded RV curve of K2-141 folded to the orbital period of the planet, as obtained using the FCO method. The best fitting circular solution is marked with a solid black line. HARPS and FIES data are shown with filled circles and squares, respectively. Different colors refer to different nights. Lower panels: the residuals to the best fitting model.