Have astronomers managed to photograph a black hole for the very first time? By using a network of radio telescopes spread over the planet to form a virtual telescope some 10,000 kilometers in diameter, researchers have completed an observation campaign of five consecutive nights. It now remains to “dissect” the images.
Black holes are among the most fascinating objects in the universe, but despite the fact that they lurk at the center of most galaxies, no one has ever been able to see them let alone photograph it. But that could be about to change. Black holes are among the most fascinating objects in the universe, but despite the fact that they lurk at the center of most galaxies, no one has ever been able to see them let alone photograph it. But that could be about to change.
By combining the instruments of seven observatories spread over the two hemispheres, at the South Pole, in the United States, in Chile and in the French Alps, the EHT project is creating a virtual telescope approximately 5,000 kilometers in diameter. In April, several teams of astronomers probed the confines of our galaxy for five nights in order to obtain the very first image of the black hole posted 26,000 light years from Earth at the center of the Path. milky. It is in fact the horizon of the black hole which will be photographed in the sub-millimeter range. But to be realized, this photo will require several months of treatment.
Indeed, observing an object of a size estimated at 25 million kilometers and four million times more massive than the Sun could seem easy as the measurements are enormous. But if the object in question does not emit any light, then the task becomes much more complicated. To do this, astronomers will use very long baseline interferometry (VLBI), a technique that links all these observatories with synchronized ultra-precise atomic clocks. Several observatories that operate in the millimeter are thus combined to form a gigantic virtual telescope some 10,000 kilometers in diameter which, it is hoped, will have enabled researchers to photograph the horizon of the black hole.
The last observation session ended on April 11, 2017. The hard drives will now have to be routed and dissected before they can have the chance to experience this world first in a few months. But then, what could our black hole look like? Probably a bright crescent of light waving around a dark spot. The light is emitted by particles of gas and dust which are accelerated to near speeds of light just before they are torn apart and consumed by the black hole.