Observations of the Galilean satellites of Jupiter with Pulkovo Normal Astrograph during 2009–2011

Abstract

The paper presents the results of observations of Jupiter and its Galilean moons, performed with the Normal Astrograph (D/F=0.33 m/3.5 m, CCD S2C, FOV 18′ × 16′) at Pulkovo observatory during 2009–2011. We obtained 140 positions of the Galilean satellites and 42 calculated positions of Jupiter in the system of UCAC4 (ICRS, J2000.0) catalogue. The equatorial coordinates of satellites have been compared to eight most current theories of planetary and satellite motion. The average residuals between the observed and calculated coordinates (O–C) using the selected theories of motion do not exceed 0.08″. The behavior and magnitudes of the (O–C) residuals in the positions of Ganymede and Callisto satellites show that the theory of their motion was elaborated worse than in the case of Io and Europa satellites. Distribution of the (O-C) residuals for Callisto differs from a normal distribution. Comparison of the calculated equatorial coordinates of Jupiter, based on the observed positions of satellites and their theoretical Jovi-centric coordinates calculated using the INPOP10 theory of planetary motion revealed satisfactory results. The average residuals are, respectively, (O–C)α = 0.040″ and (O–C)δ =–0.053″ assuming the normal distribution law.