Curated by RSF Research Staff
General Relativity Passes Test at Milky Way’s Central Black Hole
Since Einstein’s general relativity was first proposed over a hundred years ago, there have been numerous tests of proof, all of which adding support to the theory. The most significant being the correct prediction of Mercury’s perihelion orbit – which previously had no sound explanation.
A team of astronomers are now hoping to add to the ever-growing support for Einstein’s general relativity. To do this they have been tracking the paths of two stars orbiting a black hole – but not just any two stars or any black hole – they have been tracking the stars, S0-2 and S0-38, that revealed the location of our very own supermassive black hole Sagittarius A*, which has been getting quite a lot of press lately.
So far, the Californian scientists have found no evidence for deviation from a path predicted by general relativity – although the big test will be next year when the stars make their perihelion approach and get as close to the black hole as they can in their orbit. This is where the stars will experience the greatest gravitational pull from the supermassive black hole, so if there was a deviation from general relativity this is where you would expect to see it.
The team have also used this unique data set – which probes the strong gravity regime – to set constraints on the hypothetical ‘fifth’ force and the linear drift of the argument of periastron (the angle between an orbiting body's periapsis and its ascending node). Such constraints allow for improved understanding of astrophysical and gravitational theories and the further development of a unification theory.