Proceedings of the International Astronomical Union

Contributed Papers

Recent VLBA/VERA/IVS tests of general relativity

Ed Fomalonta1, Sergei Kopeikina2, Dayton Jonesa3, Mareki Honmaa4 and Oleg Titova5

a1 National Radio Astronomy Observatory, 520 Edgemont Rd, Charlottesville, VA 22903, USA email:

a2 Dept. of Physics & Astronomy, University of Missouri-Columbia, 223 Physics Bldg., Columbia, MO 65211, USA email:

a3 Jet Propulsion Laboratory, 4800 Oak Grove Ave, Pasadena, CA 91109, USA email:

a4 VERA Project Office, Mizusawa VLBI Observatory, NAOJ, 181-8588, Tokyo, Japan email:

a5 Geoscience, Australia, GPO Box 378, Canberra, ACT 2601, Australia email:


We report on recent VLBA/VERA/IVS observational tests of General Relativity. First, we will summarize the results from the 2005 VLBA experiment that determined gamma with an accuracy of 0.0003 by measuring the deflection of four compact radio sources by the solar gravitational field. We discuss the limits of precision that can be obtained with VLBA experiments in the future. We describe recent experiments using the three global arrays to measure the aberration of gravity when Jupiter and Saturn passed within a few arcmin of bright radio sources. These reductions are still in progress, but the anticipated positional accuracy of the VLBA experiment may be about 0.01 mas.


  • gravitation—quasars: individual (3C279)—relativity techniques: interferometric


Note: This material is in part based upon work supported by the National Science Foundation under Grant No. 0843236. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.