In a study published Thursday in the journal Astronomy & Astrophysics, researchers revealed for the first time that a star “danced” aroundmove like predicted with his general theory of relativity. The team of scientists studied the star for 27 years using the very large telescope of the European Southern Observatory in the Atacama Desert in Chile, in the hope of unraveling the mysteries of the gargantuan black hole in the heart of our galaxy.
Isaac Newton’s theory of gravity predicted that a star would orbit the black hole elliptically, but the researchers found that S2’s orbit was actually a rosette around the black hole, located 26,000 light years from the sun.
“Einstein’s general relativity predicts that the linked orbits of one object around another are not closed, as in Newtonian gravity, but precede forward in the plane of motion. This famous effect – seen for the first time on the orbit of the planet Mercury around the Sun – was the first proof in favor of general relativity, “said co-author Reinhard Genzel in a press release.
“A hundred years later, we have now detected the same effect in the movement of a star orbiting the compact radio source Sagittarius A * in the center of the Milky Way,” he said. “This observational breakthrough reinforces the proof that Sagittarius A * must be a supermassive black hole 4 million times the mass of the Sun. “
At its closest, S2 is less than 20 billion kilometers (about 12.5 billion miles) from Sagittarius A * – a distance that is 120 times the distance between the sun and Earth – making it one of closest stars ever seen orbiting the black hole. Researchers had to study the star for decades because it only completes one orbit every 16 years.
The constantly evolving movement of S2 corresponds exactly to that predicted by. The rosette effect, known as the Schwarzschild precession, had never been measured before for a star around a supermassive black hole, scientists said.
Research not only confirms Einstein’s theory, but it also provides crucial information about the area surrounding Sagittarius A *.
“Because S2 measurements follow general relativity so well, we can set strict limits on the amount of invisible matter, such as distributed dark matter or possible small black holes, is present around Sagittarius A *. This is of great interest in understanding the formation and evolution of supermassive black holes, “said lead scientists Guy Perrin and Karine Perraut.
Using the new ESO telescope, the team of scientists hopes to find stars in orbit even closer to the supermassive black hole.
“If we’re lucky, we could capture stars close enough to actually feel the rotation, the rotation of the black hole,” said co-author Andreas Eckart of the University of Cologne.
If they find closer stars, astronomers could measure both spin and mass, defining the space and time around Sagittarius A *. “It would again be a completely different level of testing for relativity,” said Eckart.