Albert Einstein’s famous Theory of Relativity has been confirmed once more, by astronomers studying a star orbiting around a supermassive black hole. The observations confirming this effect took place at an array of telescopes in Chile, managed by the European Southern Observatory (ESO).
In 1915, the famed physicist predicted that light from a star orbiting a massive black hole would be stretched, in a process known as a gravitational red shift. Astronomers found a star displaying nearly the exact behavior predicted by Einstein a century ago.
The nearest supermassive black hole to Earth lies 26,000 light years from us, in the heart of the Milky Way Galaxy. In May 2018, a star known as S2 passed by this object at a distance of 20 billion kilometers (12.5 billion miles). As it passed, the star was traveling at around 25 million kilometers per hour (over 15 million miles per hour) – roughly three percent of the speed of light.
“This is the second time that we have observed the close passage of S2 around the black hole in our galactic centre. But this time, because of much improved instrumentation, we were able to observe the star with unprecedented resolution. We have been preparing intensely for this event over several years, as we wanted to make the most of this unique opportunity to observe general relativistic effects,” said Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, Germany.
The center of our galaxy is surrounded by dust, but astronomers are still able to see what is happening within the area utilizing infrared light.
Nearly every prediction made by Einstein has been confirmed, most to better than one part in 10,000. However, this marks the first time this effect has been directly measured. The physicist developed two versions of the theory – special relativity, which predicts the behavior of objects traveling at vast velocities, and general relativity, which is concerned with gravitation.
As S2 continues on its journey, astronomers believe they will observe the star exhibiting another prediction of relativity – a small rotation of its orbit known as the Schwarzschild precession.