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Updated: Jan 21, 2026

Three-Dimensional Reconstruction of Orbital Fractures
Published on: May 16, 2025
Relativistic redshift of the star S0-2 orbiting the Galactic Center supermassive black hole
Tuan Do1, Aurelien Hees2,3, Andrea Ghez3
1Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, USA. tdo@astro.ucla.edu.
Abstract:
The general theory of relativity predicts that a star passing close to a supermassive black hole should exhibit a relativistic redshift. In this study, we used observations of the Galactic Center star S0-2 to test this prediction. We combined existing spectroscopic and astrometric measurements from 1995-2017, which cover S0-2's 16-year orbit, with measurements from March to September 2018, which cover three events during S0-2's closest approach to the black hole. We detected a combination of special relativistic and gravitational redshift, quantified using the redshift parameter ϒ. Our result, ϒ = 0.88 ± 0.17, is consistent with general relativity (ϒ = 1) and excludes a Newtonian model (ϒ = 0) with a statistical significance of 5σ.
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