A group of astronomers in Germany and the Czech Republic observed three stars in a cluster near the supermassive black hole at the center of the Milky Way galaxy. Using data from the Very Large Telescope in Chile, among others, the researchers tracked how the stars moved as they went around the monster black hole.
If the observations are confirmed, then it shows that Einstein’s theory of general relativity holds even under extreme conditions – in gravity fields produced by objects like the galactic center’s black hole, which contains the mass of 4 million suns.
“Most relativity tests are done with our sun and the stars, so they are in the 1-solar-mass or few-solar-mass[es] limit,” Andreas Eckart, a professor of experimental physics at the University of Cologne in Germany, who led the research team, told Space.com.
The stars used in the observations are so close to the black hole that they move at 1 or 2 percent the speed of light, Eckart said, and they approach to within only about 100 times the Earth-sun distance of the black hole itself, which is quite close by galactic standards, he said.
Mercury’s motions proved Einstein correct, but the sun’s gravity is weak compared to that of a supermassive black hole.
While gravitational lensing, the bending of light by massive objects, shows that massive objects bend space, the recent research is the first time anyone has taken precise measurements of any object orbiting so close to a black hole.