Thu. Oct 6th, 2022

Einstein was right. A successful test of the General Theory of Relativity near a black hole

Albert Einstein’s General Theory of Relativity has been confirmed in the most extreme gravitational field in the Milky Way – that is, near a supermassive black hole located at the center of our galaxy. The star, which has been observed for 26 years, named S2, has behaved in accordance with Einstein’s predictions.

The supermassive black hole located at the center of our galaxy – Sagittarius A* has a mass of four millionóin our solar. It is located 26 thousand light years from us. Wokół it a group of stars orbiting at tremendous speed. Such extreme conditions are an ideal place to study gravitational physics.

One of the stars orbiting there – named S2 – In May this year, it passed very close to Sagittarius A*. International teamó³ astronomerów had been observing it for 26 years using the instrument ofów belonging to ESO (European Southern Observatory), including the VLT (Very Large Telescope) telescope. The results of their research were published on "Astronomy & Astrophysics".

S2 circles a supermassive black hole every 16 years. However, observations of the galaxy’s center are not easy, as the view is obscured by clouds of gasóin and dustów. Astronomers have already been able to observe the passage of a star near Sagittarius A* once, but this time they had much better instruments at their disposal.

– For the second time we observed the close passage of S2 around theół of the black hole, but this time, because of the greatly improved apparatus, we were able to observe the star with unprecedented resolution – said astrophysicist Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics. – For several years we have been intensively preparing for this event. We wanted to take advantage of this unique opportunity to observe ogólnych effectóIn relativistic – added.

The S2 star passing near the black hole, at its closest point was less than 20 billionóin kilometerów from a massive monster – It is a distance four times greater than the distance between the Sun and Neptune. It may seem like a huge distance, and it certainly is, but when you’re dealing with something that has the gravitational pull of a supermassive black hole, it’s pretty close to the.

S2 during its passage near the supermassive black hole was moving at a speed of more than 25 millionóat a kilometerów per hour – is nearly 3 percent. speed of light. Researchers, thanks to the interferometer, were able to track the star’s position almost in real time (from night to night).

When S2 came so close to Sagittarius A*, according to Ogóln the Theory of Relativity, the gravitational action of a black hole should stretch the star’s light into longer wavelengths, toward the red end of the electromagnetic spectrum. And this is exactly what happened. The change in wavelength agrees perfectly with Einstein’s prediction. This phenomenon called gravitational quadrupole. By the way, astronomers for the first time observed deviations from the predictions of the simpler Newtonian theory.

Observing this phenomenon wokół Sgr A* is no mean feat. First, it is 26 thousand. light years away. In addition, the area is shrouded in a thick cloud of dust, making visible-light observations impossible. Teamó³ astronomerów used a number of extremely sensitive instrumentsóIn allowing infrared observations of GRAVITY, SINFONI and NACO installed on the VLT telescope. Using these instrumentsów, zespóThe research boat measured the velocity and mapped the orbit of S2 during a flyby near the supermassive black hole.

– Our first observations of the S2 star with the GRAVITY instrument made about two years ago showed that we would have an ideal black hole laboratory. We could even detect a faint wok glow during the close passageół black hole on most imagesów, which allowed us to precisely follow the star in its orbit, eventually leading to the detection of gravitational reddening in the S2 spectrum – explained Frank Eisenhauer of the Max Planck Institute for Extraterrestrial Physics.

However, this is not the end of Einstein’s proof of concept. Astrophysicists expect to observe another relativistic effect as S2 moves away from Sgr A*. It involves a small rotation of a star’s orbit known as Schwarzschild precession.

OgóThe Theory of Relativity, published by Einstein in 1916, has been repeatedly reviewed zaróboth on our planet and in the Solar System. Now it has also been tested in extremely strong gravity fields and has proven itself again.

„More than a century after the publication of the paper defining równania OgóThe theory of relativity, once again managed to prove that Einstein was right – in a much more extreme laboratory than could have been imagined!” – ESO wrote in a press release.