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The deflection of light induced by the Sun gravity field and measured with geodetic VLBI

Created 16/10/2025

Updated 16/10/2025

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The Sun's gravitational field deflects the apparent positions of close objects in accordance with the formulae of general relativity. Optical astrometry is used to test the prediction, but only with the stars close to the Sun and only during total Solar eclipses. Geodetic Very Long Baseline Interferometry (VLBI) is capable of measuring the deflection of the light from distant radio sources anytime and across the whole sky. We show that the effect of light deflection is equivalent to the gravitational delay calculated during the reduction of VLBI data. All reference radio sources display an annual circular motion with the magnitude proportional to their ecliptic latitude. In particular, radio sources near the ecliptic pole draw an annual circle with magnitude of 4 mas. This effect could be easily measured with the current precision of the geodetic VLBI data. Paper prepared for the Journées 2014, 22-24 September 2014, Pulkovo observatory, Russia.

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Title The deflection of light induced by the Sun gravity field and measured with geodetic VLBI
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/e91b4617-8d95-40fa-82bb-411815d9e19e
Contact Point
Geoscience Australia Data
clientservices@ga.gov.au
Reference Period 30/07/2025
Geospatial Coverage Australia
Data Portal Geoscience Australia

Data Source

This dataset was originally found on Geoscience Australia "The deflection of light induced by the Sun gravity field and measured with geodetic VLBI". Please visit the source to access the original metadata of the dataset:
https://ecat.ga.gov.au/geonetwork/srv/eng/csw/dataset/the-deflection-of-light-induced-by-the-sun-gravity-field-and-measured-with-geodetic-vlbi