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The theory of general relativity of Albert Einstein is beautiful. For a hundred or so years, he has systematically predicted all sorts of zany phenomena that scientists have observed later in space. An international team is now announcing that a 26-year observation campaign has once again confirmed the theory.
Astronomers using the very large telescope of the European Southern Observatory (VLT) observed a star orbit that is widely believed to be a supermassive black hole in the center of our Milky Way galaxy. They measured the Doppler effect of the gravity of the black hole shooting at the starlight – the effect was exactly what Einstein's theory predicted.
Astronomers have been monitoring a star called S2 with the Very Large Telescope since 1992, in the hope of using it as a probe of the gravitational field at the center of the galaxy. The star is in orbit around Sagittarius A * (a star A), a source of radio waves supposed to be a black hole of 4 million times the mass of the Sun, at a distance three times greater than that between Earth and Pluto. But considering the immense gravity of Sag A *, S2 completes its orbit in just 16 years, traveling at a maximum of 7,650 kilometers per second, or about 17 million miles per hour.
In an environment like this, the star should behave as expected by Einstein's theories on special and general relativity. Starting in 2016, researchers began watching S2 with a powerful four-telescope instrument called GRAVITY as the star approached its closest approach to Sag in May 2018. A *. The black hole distorted the space so that the star's light waves expanded, as Einstein had predicted, according to the article published in Astronomy & Astrophysics
. "The study is done with care and it is amazing how much the data accuracy has improved over the last two decades because the instrumentation has improved," he says. said Ingrid Stairs, a physicist at the University of British Columbia. study, said Gizmodo. She also pointed out that astronomers are excited by a side effect that the authors presented with their article: a new measure of accuracy of the distance from the Sun to the galactic center: 26,490 light-years, with a few exceptions
general relativity? It's a rock-solid theory that has not failed us for more than a hundred years. But there are still many mysteries unexplained throughout the universe. Some hope that the answers to these mysteries could live in tiny deviations between the predictions of general relativity and what scientists actually observe.
However, this story is not over yet. Physicists would still like to measure another prediction of general relativity, which the star should pre-test, which means that the shape of the orbit itself is spinning, more than expected by Newton. Scientists may have enough data to confirm the existence of this precession by 2020, according to the document. So the measurement will continue. Stairs said: "It will be interesting to see what they find by continuing to measure the shape of the orbit over the next few months."
[A&A via ESO]
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