Astrometric CCD observations of the third and the fourth moons of Uranus with the normal astrograph at the Pulkovo observatory

Abstract

The results of astrometric CCD observations of two major moons of Uranus (Oberon and Titania) with the Normal Astrograph (D/F = 0.33 m/3.5 m; CCD S2C with a FOV of 18′ × 16′) at the Pulkovo Observatory are presented. The observations were conducted in 2008–2011. The CCD image reduction is based on the Turner method with a reference to the UCAC3 catalogue system. The (O–C) values are calculated with the use of the MULTI-SAT server for the ephemerides of planetary moons. The obtained equatorial coordinates are compared to two modern theories of planetary motion: INPOP10 + Lainey (2008) and DE421/LE421 + Lainey (2008). The observations agree well with both theories.