Scientists at the Max Planck Institute for Extraterrestrial Physics (MPE) have now observed an effect that had been predicted by Albert Einstein with his general theory of relativity more than 100 years ago.
Using highly advanced instruments in the Very Large Telescope at the European Southern Observatory in Chile, Genzel's team were able to see through the dusty veil and take infrared and near-infrared measurements of S2.
By observing a cluster of stars near the hole, they were able to confirm a phenomenon known as "gravitational redshift". This work is further confirmation of the General theory of relativity and the first - involving object of enormous mass.
The black hole responsible was Sagittarius A* (pronounced "Sagittarius A-star"), the supermassive black hole at the center of our Milky Way galaxy. As it gets close to the black hole the very strong gravitational field causes the colour of the star to shift slightly to the red, an effect of Einstein's general theory of relativity.
It was all observed using the Very Large Telescope array in the Chilean desert. This gravitational monster is surrounded by a group of stars orbiting around it at high speed.
The orbits of stars near the Milky Way's super-massive black hole.
The study, which is published in the Astronomy & Astrophysics journal, is the culmination of more than a quarter of a century of observation by a team of experts led by Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics at Garching, Germany. In fact, the new results are inconsistent with Newtonian predictions, although they are in excellent agreement with the predictions of the general theory of relativity. "But this time, because of much improved instrumentation, we were able to observe the star with unprecedented resolution", explained in a statement Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, Germany, the leader of ESO's global team. The redshift was exactly what Einstein predicted it would be in the theory of relativity.
This time the effects of the famed scientist's principles were witnessed on the motion of a star passing through the supermassive black hole in the center of the Milky Way.
In order to create precise measurements of the changing position of S2 in order to define the shape of its orbit, scientists used SINFONI and quantified the velocity of S2 towards and away from Earth. Among these instruments was an interferometer which combines the light from four 8-meter telescopes known as the GRAVITY. In previous times, when S2 came close to the black hole, that is, in 2002, the telescopes did not have enough resources for such detailed research.
The scientists now hope to observe other theories of black hole physics, she said. During the close passage, even the faint glow around the black hole could be detected on most of the images.
The boffins selected one star, S2, to follow.
This animation shows the orbit of the star S2 around the supermassive black hole at the heart of the Milky Way.
Albert Einstein dedicated his life to the pursuit of knowledge, even if he couldn't always prove that his theories made sense. Several of its components have been proven over the years, but this is the latest.
"It's really the first time a [gravitational red shift] has been seen in such a clear fashion on an object that is moving", said Paumard.