标题： 2006 QV89虚拟撞击器的消除通过深度未检测 显示英文标题

标题： Elimination of a virtual impactor of 2006 QV89 via deep non-detection

摘要： 由于发现的近地天体数量越来越多（并且还在增长），其中一些天体在轨道被确定之前就丢失了，从而无法确保长期恢复。这些天体中有一部分存在与地球碰撞的不可忽视的可能性。我们提出了一种有针对性的观测方法，通过获取该天体如果处于碰撞轨道时所在区域的深空图像，从而消除了这种风险。2006 QV89就是其中之一，在2019年9月9日有与地球碰撞的可能。它的位置不确定性（约为1度）和暗弱（低于V$\sim$24）使其成为传统直接恢复的困难候选对象。然而，虚拟撞击器的位置可以非常精确地确定。2019年7月，2006 QV89的虚拟撞击器位置特别有利，不确定性区域非常小，预计视星等为V$<$26。该区域使用ESO的超大望远镜进行成像，在ESA/ESO近地天体合作背景下，结果得到了非常严格的无检测结果。这导致虚拟撞击器被排除，即使没有实际恢复2006 QV89，也表明它并不构成威胁。这种对虚拟撞击器的深空无检测方法展示了消除其他难以恢复的近地天体威胁的巨大潜力。 显示英文摘要

摘要： As a consequence of the large (and growing) number of near-Earth objects discovered, some of them are lost before their orbit can be firmly established to ensure long-term recovery. A fraction of these present non-negligible chances of impact with the Earth. We present a method of targeted observations that allowed us to eliminate that risk by obtaining deep images of the area where the object would be, should it be on a collision orbit. 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 degree) and faintness (below V$\sim$24) made it a difficult candidate for a traditional direct recovery. However, the position of the virtual impactors could be determined with excellent accuracy. In July 2019, the virtual impactors of 2006 QV89 were particularly well placed, with a very small uncertainty region, and an expected magnitude of V$<$26. The area was imaged using ESO's Very Large Telescope, in the context of the ESA/ESO collaboration on Near-Earth Objects, resulting in very constraining a non-detection. This resulted in the elimination of the virtual impactor, even without effectively recovering 2006 QV89, indicating that it did not represent a threat. This method of deep non-detection of virtual impactors demonstrated a large potential to eliminate the threat of other-wise difficult to recover near-Earth objects