Squared visibilities V² for VLTI/GRAVITY observations (March 14, 2017 and April 27, 2017; blue), synthetic V² (orange), and residuals (red). The sinusoidal dependence on the baseline B/λ essentially corresponds to a wide binary ((Ac1+Ac2)+(Aa1+Aa2)). Disks of individual stellar components cannot be resolved (at 0.08 mas, which correspond to a drop in V² of only 0.01 at the longest baseline).