Relativistic redshift of the star S0-2 orbiting the Galactic Center supermassive black hole.
Tuan DoAurelien HeesAndrea GhezGregory D MartinezDevin S ChuSiyao JiaShoko SakaiJessica R LuAbhimat K GautamKelly Kosmo O'NeilEric E BecklinMark R MorrisKeith MatthewsShogo NishiyamaRandy CampbellSamantha ChappellZhuo ChenAnna CiurloArezu DehghanfarEulalia Gallego-CanoWolfgang E KerzendorfJames E LykeSmadar NaozHiromi SaidaRainer SchödelMasaaki TakahashiYohsuke TakamoriGunther WitzelPeter WizinowichPublished in: Science (New York, N.Y.) (2019)
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.