Astrometric observations of the main Uranian satellites at the Pulkovo Observatory in 2007–2016

Abstract

In this paper we present the results of the observations of the Uranian satellites made with the 26-in. refractor at the Pulkovo Observatory in 2007–2016. Almost 7000 CCD frames were analyzed and reduced using the UCAC4 catalog. Coordinates of Uranus were determined indirectly using the satellite positions and their ephemeris relative to the planet. The (O-C) differences were calculated for each object using the INPOP13c planetary theory and Lainey's theory of the satellites' motion. The positioning accuracy is better than 0.5arcsec. The mean values of (O-C) do not exceed 0″.1 in RA and DEC correspondingly (Ariel: 0″.043 and −0″.074; Umbriel: 0.″025 and −0.″069; Titania: −0.″009 and −0.″014; Oberon: −0.″001 and −0″.019; Uranus: 0.″002 and −0.″016). They are in a good agreement with the ephemeris.