Since VLBI techniques produce a microarcsecond positional accuracy of celestial objects, tests of GR using radio sources as probes of a gravitational field have been made. We present the results from two recent tests using the VLBA: in 2005, the measurement of the classical solar deflection; and in 2002, the measurement of the retarded gravitational deflection associated with Jupiter. The deflection experiment measured γ to an accuracy of 3 × 10-4 the Jupiter experiment measured the retarded term to 20% accuracy. The controversy over the interpretation of the retarded term is summarized.
A Giant Step: from Milli- to Micro-arcsecond Astrometry
- Pub Date:
- July 2008
- techniques: interferometric;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Astrophysics - Instrumentation and Methods for Astrophysics
- 4 pages: IAU240