The Measurement of the Light Deflection from Jupiter: Experimental Results

We have determined the relativistic light deflection of the quasar J0842+1835 as Jupiter passed within 3...7 on 2002 September 8, by measuring the time delay using the Very Long Baseline Array (VLBA) and Effelsberg radio telescopes at 8.4 GHz. At closest approach, general relativity (GR) predicts a radial (static) deflection of 1190 (mu)as and a tangential (retarded) deflection in the direction of Jupiterʹs motion of 51 (mu)as. Our experiment achieved an rms position error of <~10 (mu)as and measured this retarded deflection to be 0.98 ± 0.19 (rms error) times that predicted by GR. The increased positional accuracy for this VLBI phase-referencing experiment was achieved by using two calibrator sources. Comments on the interpretation of this experiment are given.