A historic breakthrough in the world of science. Astronauts have just released the very first image of a black hole located at the heart of our galaxy, after years of research. This snapshot confirms in passing the theory of general relativity published by Albert Einstein.
A monster four million times more massive than our Sun
The cosmic monster answering to the name of Sagittarius A, which sits at the center of our galaxy, the Milky Way, 27,000 light years from Earth has just been photographed and shown to the whole world. Scientists had already spotted it somewhat, when observing stars orbiting an invisible, compact and very massive object in the center of the Milky Way. This strongly suggested that this object was a black hole.
Sagittarius A is therefore a supermassive black hole, consisting of a dark central region (called a shadow) surrounded by a bright ring-shaped structure, which is an incandescent gas. The image is historic. It was produced by a global research team called the Event Horizon Telescope (EHT) Collaboration, based on observations from a large network of radio telescopes. “We were amazed at how well the size of the ring matched the predictions of Einstein’s theory of general relativitysaid EHT project scientist Geoffrey Bower of the Institute of Astronomy and Astrophysics at Academia Sinica in Taipei:
These unprecedented observations have dramatically improved our understanding of what is happening at the very center of our galaxy, and offer new insights into how these giant black holes interact with their surroundings.
Einstein’s theory of relativity validated
This announcement proves once again that the same physical mechanisms are at work at the heart of two systems of different sizes. But it is also and above all the theory of general relativity developed by Einstein which is at the heart of this observation. As a reminder, the theory of general relativity published in 1915 demonstrates that the gravitational attraction observed between masses is caused by a deformation of space and time by these masses.
Our colleagues from Huffpost interviewed Frédéric Gueth, researcher at the CNRS. This is what he says: “with this image from a much closer source, we have a lot of precise information that allows us to confirm that there is no deviation from the predictions of general relativity”.
The photo of Sagittarius A* is like this undeniable proof that the theory works everywhere, even in the most extreme environments, such as black holes for example.
This advance follows the publication in 2019 of the first image of a black hole, called M87, at the center of the more distant galaxy Messier 87. The two look very similar, although that of our galaxy is more than a thousand times larger. small and less massive than M87.
“We have two completely different types of galaxies and two very different masses of black holes, but near the edge of these black holes they look amazingly similar.“, explains to Midi-Libre Sera Markoff, co-president of the scientific council of the EHT and professor of theoretical astrophysics at the University of Amsterdam, in the Netherlands.
This tells us that general relativity rules these objects up close, and that any differences we see farther away must be due to dissimilarities in the matter surrounding the black holes.”
All therefore agree to justify and validate one of the most famous theories in the world. A day to mark with a cross in the space and scientific field.
To go further, you can also listen to the “howl” of a star being swallowed by a black hole, right here.