For the first time astronomers have detected light coming from a black hole, confirming Albert Einstein’s theory of general relativity, more than a hundred years later.
Einstein in 1916 had predicted that a black hole’s gravity should theoretically be able to bend light around it.
A black hole is formed when a star dies and emits a high gravitational field that the matter gets squeezed into the small space under it, trapping the light of the dying star.
Because the gravitational pull of black holes is so strong, scientists have long believed that any light will be trapped and nothing can escape its grasp.
However, while the light cannot escape a black hole, its extreme gravity warps space around it, which allows light to ‘echo’, bending around the back of the object.
It started with the corona
The light was detected by coincidence when researchers were studying a feature known as the corona, a form of X-Ray or bright light that is formed by materials falling into a supermassive black hole.
The discovery was made by astrophysicists at Stanford University in California using for the first time the European Space Agency’s (ESA) XMN Newton and NASA’s NuSTAR space telescopes to look at a supermassive black hole in the centre of the spiral galaxy, Zwicky, which is 1, 800 million light-years away from earth.
"Any light that goes into that black hole doesn’t come out, so we shouldn’t be able to see anything that’s behind the black hole," says Dan Wilkins, the author of the study and a research scientist at Stanford. "The reason we can see that is because that black hole is warping space, bending light and twisting magnetic fields around itself."
By observing the light's journey around the back of the black hole, the researchers hope to understand more about what goes behind these gravitational vortexes and how they impact what we know about magnetic fields and physics.
The discovery and work was first described in a study published in the Nature journal last week.