Variation of the mean longitudinal magnetic field of HR 5624. The dark symbols show ⟨ B_z ⟩ measurements derived in this study from the HARPSpol (red circles) and ESPaDOnS (blue rhombs) observations. The green squares show the Balmer line photopolarimetric measurements by Landstreet (1990). The upper and lower panels illustrate phasing of the ⟨ B_z ⟩ data with the rotational periods 0.877476 d and 0.877483 d, respectively.