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Star catalog position and proper motion corrections in asteroid astrometry II: The Gaia era

Eggl, Siegfried; Chesley, Steven R.; Farnocchia, Davide +1 more

Astrometric positions of moving objects in the Solar System have been measured using a variety of star catalogs in the past. Previous work has shown that systematic errors in star catalogs can affect the accuracy of astrometric observations. That, in turn, can influence the resulting orbit fits for minor planets. In order to quantify these systema…

Re-reduction of CCD observations of Triton in 1996-2006 with Gaia DR2 and comparison with ephemerides

Cheng, X.; Yan, D.; Qiao, R. C. +1 more

The release of new high-precision and high-density catalogue Gaia DR2 brings new opportunities and challenges to high-precision astrometry. The early CCD images of planet satellites can be re-processed so as to give positions that are much more accurate than those initially obtained. Based on Gaia DR2 catalogue, the early CCD images of Triton take…

New astrometric positions of the Jovian irregular satellites Elara and Pasiphae in 2016-2018

Cheng, X.; Zhang, H. Y.; Yan, D. +5 more

A total of 372 astrometric positions of Jovian irregular satellites Elara and Pasiphae were obtained during three successive oppositions in 2016, 2017, and 2018, by 1 m telescope at Yunnan Observatory. Based on Gaia DR2 catalogue, 196 new positions of Elara and 176 new positions of Pasiphae were collected. We compared our observations to the theor…