Radio Interferometric Test of the General Relativistic Light Bending Near the Sun

Abstract

We have used radio interferometry to measure the deflection of a radio source as it passed the sun. This deflection is a separable combination of refraction in the coronal electron plasma and the general relativistic effect. The observed deflection was ${1.04}_{-0.10\mathrm{}}^{+0.15\mathrm{}}$ times that predicted by Einstein's theory of general relativity. The observation also yielded a reasonable value for the coronal electron density.