Stack of the background-subtracted frames, aligned on the expected position of the centre VI. The position of the eastern- and westernmost VIs are also indicated. 2006 QV₈₉ appearing between these two extremes would be on a collision orbit. The grey scale is the same as in Fig. 2. Artificial objects were introduced in the images; their magnitudes are indicated. As a reference, 2006 QV₈₉ is expected at mag ~23.7 and must be brighter than 26.