Deflection of Light by the Sun and Comparison with General Relativity

2019 ◽  
pp. 396-404
2018 ◽  
Vol 618 ◽  
pp. A8 ◽  
Author(s):  
O. Titov ◽  
A. Girdiuk ◽  
S. B. Lambert ◽  
J. Lovell ◽  
J. McCallum ◽  
...  

Context. We highlight the capabilities of geodetic VLBI technique to test general relativity in the classical astrometric style, i.e. measuring the deflection of light in the vicinity of the Sun.Aims. In previous studies, the parameterγwas estimated by global analyses of thousands of geodetic VLBI sessions. Here we estimateγfrom a single session where the Sun has approached two strong reference radio sources, 0229+131 and 0235+164, at an elongation angle of 1–3°.Methods. The AUA020 VLBI session of 1 May 2017 was designed to obtain more than 1000 group delays from the two radio sources. The solar corona effect was effectively calibrated with the dual-frequency observations even at small elongation.Results. We obtainedγwith a greater precision (0.9 × 10−4) than has been obtained through global analyses of thousands of standard geodetic sessions over decades. Current results demonstrate that the modern VLBI technology is capable of establishing new limits on observational tests of general relativity.


2007 ◽  
Vol 3 (S248) ◽  
pp. 290-291 ◽  
Author(s):  
A. Vecchiato ◽  
M. G. Lattanzi ◽  
M. Gai ◽  
R. Morbidelli

AbstractGAME (Gamma Astrometric Measurement Experiment) is a concept for an experiment whose goal is to measure from space the γ parameter of the Parameterized Post-Newtonian formalism, by means of a satellite orbiting at 1 AU from the Sun and looking as close as possible to its limb. This technique resembles the one used during the solar eclipse of 1919, when Dyson, Eddington and collaborators measured for the first time the gravitational bending of light. Simple estimations suggest that, possibly within the budget of a small mission, one could reach the 10−6level of accuracy with ~106observations of relatively bright stars at about 2° apart from the Sun. Further simulations show that this result could be reached with only 20 days of measurements on stars ofV≤ 17 uniformly distributed. A quick look at real star densities suggests that this result could be greatly improved by observing particularly crowded regions near the galactic center.


1980 ◽  
Vol 22 (12) ◽  
pp. 2947-2949 ◽  
Author(s):  
Reuben Epstein ◽  
Irwin I. Shapiro
Keyword(s):  
The Sun ◽  

2016 ◽  
Vol 4 (2) ◽  
pp. 52 ◽  
Author(s):  
V.K. Shchigolev

A new approach in studying the planetary orbits and deflection of light in General Relativity (GR) by means of the Variational iteration method (VIM) is proposed in this paper. For this purpose, a brief review of the nonlinear geodesic equations in the spherical symmetry spacetime and the main ideas of VIM are given. The appropriate correct functionals are constructed for the geodesics in the spacetime of Schwarzschild, Reissner-Nordström and Kiselev black holes. In these cases, the Lagrange multiplier is obtained from the stationary conditions for the correct functionals. Then, VIM leads to the simple problem of computation of the integrals in order to obtain the approximate solutions of the geodesic equations. On the basis of these approximate solutions, the perihelion shift and the light deflection have been obtained for the metrics mentioned above.


Author(s):  
Francesco Topputo ◽  
Diogene A. Dei Tos ◽  
Mirco Rasotto ◽  
Masaki Nakamiya

1996 ◽  
Vol 172 ◽  
pp. 3-16
Author(s):  
Bruno Morando

Lagrange and Laplace were two of the first members of Bureau des longitudes which, among other tasks, were responsible for the improvement of astronomical tables and the progress of celestial mechanics. Between 1795 and 1850, many improved tables were published under the auspices of Bureau des longitudes: tables of the Sun by Delambre (1806), of the Moon by Burg (1806), Burckhardt (1812) and Damoiseau (1828), of Jupiter, Saturn and Uranus by Bouvard (1808, 1821), of Mercury by Le Verrier (1844), of the satellites of Jupiter by Delambre (1817) and Damoiseau (1836). In his tables, Bouvard showed there was a problem for Uranus. This led to the calculations of the elements of an unknown planet by Le Verrier and Adams and the discovery of Neptune in 1846. Le Verrier's calculations were published in Connaissance des Temps for 1849. In the second half of the XIXth century, two prominent members of Bureau des longitudes, Le Verrier and Delaunay, made major contributions to celestial mechanics by building elaborate theories for the motions of the Sun, the planets and the Moon. Other theories, which improved the above, appeared elsewhere at the end of the century, especially those of Newcomb, Hill and Brown. During the first half of the XXth century, there was a decline of the studies in celestial mechanics which seemed to have reached its limits owing to the difficulties of the computations involved. Yet Sampson's theory of the motion of the satellites of Jupiter and Chazy's first attempts to introduce general relativity into classical celestial mechanics should be quoted. In 1961, thanks to A. Danjon, Bureau des longitudes was reorganized so that its computation service became a research laboratory where, since then, important work in the theories of the planets, the Moon and the satellites has been made.


1960 ◽  
Vol 38 (6) ◽  
pp. 853-865 ◽  
Author(s):  
Luise Herzberg

The differences between the wavelengths at the solar limb and at the center of the disk have been measured for lines of Fe I, Si I, and Ca II in the λ8500 Å and λ8900 Å regions of the spectrum. The values of the limb–center displacements (in km/sec) of the Fe I lines in the two wavelength regions studied are found to be the same as those obtained by M. G. Adam for neutral metal lines at λ6100 Å. The limb–center displacements of the Si I lines are similar in magnitude and in the same direction as those of Fe I. Although the data are insufficient to decide the question as to term dependence of the solar wavelength shifts of Si I, any relation to the shifts observed in a laboratory light source can be excluded. For the Ca II lines at λ8500 Å and λ8900 Å, corresponding to two different transitions, the limb–center displacements differ from each other both in magnitude and in direction. The limb–center displacements of the λ8900 Å Ca II lines are smaller than those of the Fe I lines, while those of the λ8500 Å Ca II lines are significantly larger and in direction opposite to those observed for lines of Fe I.Where possible, comparison has been made between the wavelengths observed at limb and center of the disk and the solar wavelengths predicted by General Relativity Theory. In all cases the wavelengths at the limb were found to be closer to the predicted values than the wavelengths measured at the center of the disk. While for the lines of Fe I the predicted solar wavelengths and those observed near the limb (r/R = 0.982) are in good agreement, the wavelengths close to the solar limb of the λ8500 Å Ca II lines are found to be significantly larger than those predicted by relativity theory.


Author(s):  
Gerard Gilmore FRS ◽  
Gudrun Tausch-Pebody

Einstein became world famous on 7 November 1919, following press publication of a meeting held in London on 6 November 1919 where the results were announced of two British expeditions led by Eddington, Dyson and Davidson to measure how much background starlight is bent as it passes the Sun. Three data sets were obtained: two showed the measured deflection matched the theoretical prediction of Einstein's 1915 Theory of General Relativity, and became the official result; the third was discarded as defective. At the time, the experimental result was accepted by the expert astronomical community. However, in 1980 a study by philosophers of science Earman and Glymour claimed that the data selection in the 1919 analysis was flawed and that the discarded data set was fully valid and was not consistent with the Einstein prediction, and that, therefore, the overall result did not verify General Relativity. This claim, and the resulting accusation of Eddington's bias, was repeated with exaggeration in later literature and has become ubiquitous. The 1919 and 1980 analyses of the same data provide two discordant conclusions. We reanalyse the 1919 data, and identify the error that undermines the conclusions of Earman and Glymour.


Sign in / Sign up

Export Citation Format

Share Document