Black Hole Sagittarius A* possesses four million times the mass of our sun and is about 26,000 light years, or 9.5 trillion km, away from Earth.
Astronomers have captured an image of the supermassive black hole at the center of our galaxy for the very first time.
Called Sagittarius A*, the object is located in the middle of the Milky Way and devours any matter within its huge gravitational pull.
The image, produced by a global team of scientists known as the Event Horizon Telescope (EHT) Collaboration, is the first, direct visual confirmation of the presence of this invisible object, and comes three years after the very first image of a black hole from a distant galaxy.
The image provided overwhelming evidence that the object is a black hole, and offers useful clues about how the supermassive black hole works.
The Event Horizon Telescope Collaboration used observations from a worldwide network of eight excising radio telescopes to create this image.
In 2009, Dr. Doeleman and his colleagues formed the Event Horizon Telescope, named after the point of no return around a black hole
The image depicts not the black hole itself, because that is completely dark, but the glowing gas that encircles the phenomenon, which is four million times more massive than the Sun, in a bright ring of bending light
EHT project scientist Geoffrey Bower of of Taiwan’s Academia Sinica said: “These unprecedented observations have greatly improved our understanding of what happens at the very centre of our galaxy,”
Bower also said in a statement provided by the French National Centre for Scientific Research (CNRS) that the observations had offered “new insights on how these giant black holes interact with their surroundings”.
The results are published in The Astrophysical Journal Letters.
The University of Arizona’s Feryal Ozel called the black hole “the gentle giant in the centre of our galaxy” while announcing the new image.
Prof Sera Markoff, an astrophysicist at the University of Amsterdam and co-chair of the EHT Science Council, said: “The Milky Way’s black hole was our main target, it’s our closest supermassive black hole and it’s the reason we set out to do this thing in the first place. It’s been a 100-year search for these things and so, scientifically, it’s a huge deal.”
The image provides compelling proof that there is a black hole at the centre of the Milky Way, which had been the working assumption of mainstream astronomy. A minority of scientists had continued to speculate about the possibility of other exotic objects, such as boson stars or clumps of dark matter.
“I’m personally happy about the fact it really drills home the fact that there is definitely a black hole at the centre of our galaxy,” said Dr Ziri Younsi, a member of the EHT collaboration based at University College London.
The latest observations also appear to show that our black hole’s angle of rotation is not neatly aligned with the galactic plane, but is off-kilter by about 30 degrees, and hint at spectacular magnetic activity similar to that seen in the sun’s atmosphere. Beyond the science, astronomers acknowledged an emotional connection with finally seeing the enigmatic object about which our home galaxy revolves.
Ultimately, scientists hope that observing a range of black holes – fairly dormant giants like ours and turbulent giants like M87* – might help answer a chicken-and-egg question about the evolution of galaxies.
M87 is 55 million light-years away in the Virgo Galaxy cluster and has a mass about 6.5 billion times that of our sun. The bright circle of gas and dust that collects and swirls around it is known as an accretion disk. It takes many days to orbit around this gargantuan object. That means that when the EHT team shines their telescopes on it for hours — using a technique called very long baseline interferometry that works like taking a long exposure image on a camera — any change appears very gradually.
Sgr A*, on the other hand, is on the small side. If it was the size of a doughnut, M87 would be the size of a football stadium. This means superheated gas, which travels at near-light speed and takes days to orbit M87, only takes minutes to orbit Sgr A*, which is why there is so much motion blur in the image.