Elimination of a virtual impactor of 2006 QV89via deep non-detection

Context. As a consequence of the large (and growing) number of near-Earth objects discovered, some are lost before their orbits can be firmly established and long-term recovery ensured. A fraction of these objects present non-negligible chances of impact with the Earth. We present a method of targeted observations that allow us to eliminate that risk by obtaining deep images of the area where the object would be, should it be on a collision orbit. Aims. 2006 QV89 was one of these objects, with a chance of impact with the Earth on 2019 September 9. Its position uncertainty (of the order of 1°) and faintness (below V ~ 24) made it a difficult candidate for a traditional direct recovery. However, the position of the virtual impactors could be determined with excellent accuracy. Methods. In July 2019 the virtual impactors of 2006 QV89 were particularly well placed within a very small uncertainty region, and with an expected magnitude of V < 26. The area was imaged using the ESO Very Large Telescope in the context of the ESA/ESO collaboration on near-Earth objects, resulting in a strongly constrained non-detection. Results. We eliminated the virtual impactor, even without effectively recovering 2006 QV89, indicating that it did not represent a threat. Conclusions. This method of deep non-detection of virtual impactors demonstrated a large potential to eliminate the threat of otherwise difficult-to-recover near-Earth objects.