26,000 light-years is one of the black holes supermbadive – that is to say having a mbad four million times greater than that of the Sun – the nearest of the Earth, ] excellent place to make observations . Like those made by the Southern European Observatory (ESO) based in Chile, thanks to the VLT telescope, he was able to prove that the theory of relativity general by Albert Einstein is also fulfilled in these objects. What have the researchers observed?

A group of stars bypbades the extreme magnetic field of this black hole. For this reason, it is the ideal place to explore gravitational physics. In this case, they followed the star S2 for its pbadage very close to the black hole during the last month of May. At the closest point, according to the researchers, the star was less than 20 billion kilometers from the black hole and its speed was 25 million kilometers per hour, or nearly 3% of the speed of light [19659003] Astrophysicists compared the position and velocity measurements of GRAVITY and SINFONI, two VLT instruments, respectively, with previous observations of S2 using other instruments and whose results were revealed last year. Newtonian gravity, general relativity and other theories of gravity . And they gave the result that Newton's predictions are inconsistent. On the other hand, they are in agreement with the predictions of general relativity predicted by Einstein. More than a hundred years after publishing his article presenting the equations of general relativity, was shown just .

"Extremely accurate" measures, as reported by ESO in a press release. press, were conducted by an international team led by Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, Germany. They have done it in collaboration with researchers from all over the world, at the Paris-PSL Observatory, at the University of Grenoble Alpes, at the CNRS, at the Max Planck Institute in Paris. Astronomy, at the University of Cologne, at the Portuguese Center of Astrophysics and Gravitação and It The results are the culmination of 26 years of observations more and more precise from the center of the Milky Way using instruments of the ESO

Second observation of S2

a year ago, this star was already the protagonist of a study that has tried to demonstrate the theory of Albert Einstein . However, I was not yet in a position as close as it was last May, so they could only see the potential of this small laboratory in paradise. "Our first observations of S2 with GRAVITY, two years ago already, showed that we would have the ideal laboratory of the black hole ," adds Frank Eisenhauer (MPE), GRAVITY's principal investigator and SINFONI spectrograph. "During the pbadage of the star we could even detect the faint glow around the black hole in most of the images, which allowed us to accurately track S2 into its orbit which eventually led to the detection of the gravitational red shift in the star spectrum.

"This time, thanks to the improvement of the instrumentation, we could observe the star with unprecedented resolution ", explains Genzel, for this event for several years, since we wanted to take full advantage of this unique opportunity to observe the general relativistic effects." And so it was, scientists have found one of these long-awaited effects, the transition to gravitational red

ESO / M. Kornmesser

In the case of S2 they observed this effect, which is in agreement with that predicted by Einstein's theory [19] 459005] which is produced by that due to the gravitational field of the black hole stretches the light produced by the star. The gravitational red shift can be seen because there is a change in the wavelength of the S2 light, which is pulling red in the electromagnetic spectrum. But, most importantly, it is the first time that this prediction was observed in the movement of a star around a supermbadive black hole.

For astrophysicists, it is "very important to verify that these laws [de la física] are still valid where the gravitational fields are much stronger," explains Françoise Delplancke, head of the engineering department. ESO systems. The importance of these observations.

Researchers expect us to continue looking at this supermbadive black hole, suppose to find other relativistic effects sooner rather than later. One example that scientists hope to see in the next few years is a small rotation of the orbit of the star – known as the Schwarzschild metric – while it is moving away from this. object.