Abstract
For an observer on Earth the general theory of relativity (GR) predicts an apparent outward displacement of a star seen at the Sun's limb of 1.75 arc s. A generalized formulation for gravitational deflection of light1 includes a parameter γ which ranges from 1 (GR) to −1 (no deflection). Early total eclipse measurements2 constrained γ by 20–40%, permitting alternative gravitational theories (for example, ref. 3). Radio interferometer measurements of deflections of extragalactic objects4,5 and timing measurements of spacecraft signals6 have all been consistent with GR with increasing accuracy. We now report the most sensitive measurement of deflection so far achieved, in which very long baseline interferometry (VLBI) observations yield a value of γ of 1.008 with a 1 σ formal standard error of ±0.005.
Similar content being viewed by others
References
Misner, C. W., Thorne, K. S. & Wheeler, J. A. Gravitation, 1103 (Freeman, San Francisco, 1973).
von Kluber, H. in Vistas in Astronomy Vol. 3 (ed. Beer, A.) 47 (Pergamon, New York, 1960).
Brans, C. & Dicke, R. H. Phys. Rev. 124, 925 (1961).
Shapiro, I. I. Science 157, 306–307 (1967).
Fomalont, E. B. & Sramek, R. A. Comments Astrophys. Space Phys. 7 : 19 (1977); Phys. Rev. Lett. 36, 1475–1478 (1976).
Reasenberg, R. D. et al. Astrophys. J. Lett. 234, L219–L221 (1979).
Wilkins, G. A. & Feissel, M. Proj. MERIT: Report on the Short Campaign and Grasse Workshop with Observations and Results on Earth-Rotation During 1980, August–October (Royal Greenwich Observatory, Herstmonceux, 1982).
Robertson, D. S. & Carter, W. E. in High Precision Earth Rotation and Earth-Moon Dynamics (ed. Calame, O.) 97–122 (Reidel, Dordrecht, 1982).
Carter, W. E. et al. Science 224, 957–961 (1984).
Carter, W. E. in Multidisciplinary Use of the Very Long Baseline Array, 44–51 (National Academy, Washington DC, 1983).
Rogers, A. E. E. et al. Science 219, 51–54 (1983).
Wahr, J. M. thesis, Univ. Colorado (1979).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Robertson, D., Carter, W. Relativistic deflection of radio signals in the solar gravitational field measured with VLBI. Nature 310, 572–574 (1984). https://doi.org/10.1038/310572a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/310572a0
- Springer Nature Limited
This article is cited by
-
Gravitation and inertia; a rearrangement of vacuum in gravity
Astrophysics and Space Science (2010)
-
New measurement of solar gravitational deflection of radio signals using VLBI
Nature (1991)
-
Evidence from solar seismology against non-standard solar-core models
Nature (1990)
-
General relativistic measurements with satellite laser ranging, lunar laser ranging and very long baseline interferometry
Il Nuovo Cimento C (1990)