Long-term Stability of Six Neptunian Trojans

Abstract

Abstract This paper explores the long-term stability of six Neptunian Trojans. In contrast with other Neptunian Trojans, these objects have previously unknown lifetimes and larger orbital uncertainties due to their shorter observational arcs. We obtained new astrometry of the six Trojans using the Magellan telescope, refit their orbits, and performed Gyr-long numerical integrations to estimate their lifetimes. The results show that five of these six objects are stable over Gyr timescales. The remaining object, 2015 VV165, has a calculated lifetime of 0.691 ± 0.001 Gyr, which is similar to the previous estimate of 0.65 Gyr. As a result, the shorter lifetime of this latter object is most likely physical (rather than due to uncertainties in its orbital determination).