Elimination of a virtual impactor of 2006 QV89 via 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.