A team of international scientists proved for the first time Einstein’s predictions of what happens to the motion of a star passing close to a super-massive black hole. The group of scientists has been observing a star in the Milky Way for a long time. Einstein’s 100-year-old theory of relativity is that according to Einstein, the light from stars would be stretched to longer wavelengths by the extreme gravitational field of a black hole and that the star would appear redder. This effect is generally known as gravitational red shift.
The group of scientists started to monitor the central area of the Milky Way at the European Southern Observatory 26 years ago. They were using their Very Large Telescope to observe the motion of stars near the super-massive black hole. The black hole is 26,000 light years away from Earth and has mass 4 million times that of the Sun. The scientists selected one star called S2 and it takes 16 years to complete one orbit. Scientists knew that after completing its journey around its star, it would return close to the black hole in 2018.
The scientists have found out that the star’s orbital velocity increased to more than 25 million kph as it approached the black hole and its wavelength stretched as it sought to escape the gravitational pull of the super-massive black hole which in turn made the star turn red.
This was the first time we could test directly Einstein’s theory of general relativity near a supermassive black hole. At the time of Einstein, he could not think or dream of what we are showing today. – Frank Eisenhauer, senior astronomer at the Max Planck Institute for Extraterrestrial Physics
“This is the first step on a long road that the team has done over many years and which we hope to continue in the next years,” MPE’s Reinhard Genzel, who led the international team said.