Superluminal Motion of 3C273B and the Apparent Right Ascension Shift

The effect of the superluminal motion of 3C 273b was observed on the fringe amplitudes obtained in VLBI experiments which have been conducted on the baselines between Japan and United States since 1984 under the Crustal Dynamics Project. The speed was 0.7 mas/year and the direction was -83° in the position angle. The effect was also confirmed as the apparent right ascension shift of the source.