L_acc variability across the 12 epochs (upper panel) and folded in phase with the rotation of the star (lower panel). The period is 3.71 days (Stempels et al. 2007). The colour of the data points in the lower panel indicates the cycle of rotation of the star. The parameters of the sinusoidal fit are: amplitude = −0.4 ± 0.1 L_⊙ and offset = 0.8 ± 0.1 L_⊙. The blue dashed line indicates the median value of accretion luminosity of 0.48 L_⊙.