Precise Positions of Triton in 2010–2014 based on Gaia-DR2

With unique orbital and physical characteristics, Triton is a very important target because it may contain information of the origin and evolution of the solar system. Besides space explorations, ground-based observations over long time also play a key role on research of Triton. High-precision positions of Triton obtained from ground telescopes are of great significance for studying its orbital evolution and the physical properties of Neptune. As a long-term observational target, Triton has been observed by the 1.56 m telescope of Shanghai Astronomical Observatory since 1996. In this paper, based on our AAPPDI software and with Gaia DR2 as the reference catalog, 604 positions of Triton during 2010–2014 are calculated, with standard errors of 19–88 mas. A comparison between our results and the ephemeris (DE431+nep096) is also given.