Periodogram and the magnetic phase curve for the period P = 51.7 ± 0.06 d. Left: periodogram based on all Narval and one ESPaDOnS ⟨B_z⟩ measurements from 2012 and eight HARPSpol ⟨B_z⟩ measurements recorded until 2019. The red line is for observations and the blue line for the window function. Right: ⟨B_z⟩ measurements (magenta circles for Narval and ESPaDOnS and blue circles for HARPS) phased with P = 51.7 ± 0.06 d. The sinusoidal fit is shown with the red line.