Brγ interferometric aperture synthesis images from the May-June 2017 data. The Doppler velocity of each frame is labeled in the images. For all the panels, east is to the left and north to the top and the displayed FOV corresponds to 36 × 36 mas. The small white ellipse shown in the lowermost-left panel corresponds to the synthesized beam (the detailed PSF is shown in Fig. D.1). Above all the images, the GRAVITY spectrum is shown and the different positions where the images are reconstructed across the line are labeled with a colored square, which is also plotted in the images for an easy identification. Due to the sparseness of the u−v coverage, the quality of these reconstructed images is limited, creating a clumpy fine structure and a cross-like shape superimposed on the source’s brightness distribution. Therefore, they cannot be properly compared with the GRAVITY 2016 data presented in this work.