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There is a monster in the heart of our galaxy. And, for the first time, we saw it feed.
We know that black holes exist. It's just that we have not really seen them.
They are black. They are so strong that even the light can not escape.
The best science that can hope for is to capture the shadow of a beast such as Sagittarius-A, the supermassive black hole at the heart of our galaxy, as it wraps around matter.
It's now here.
Telescopes, finely tuned to peer through the gas clouds that separate us from the heart of the galaxy, have spotted something "flickering" in a narrow circle. It evolves so rapidly and in such a tight orbit that it is at the limit of the laws of physics.
This means that everything that this light spot is wavering breaks these laws.
It means a black hole.
It turns 323 million kmh at the edge of space and time that lose their meaning. By looking at it, astronomers hope to learn what is really happening at this point of intersection.
But this has already given us our best insight into what a black hole looks like.
"Astronomers probably think that the existence of the black hole is an old news", Michael Brown, astrophysicist at Monash University, said. "What's fun is how close we are to the event horizon."
But perhaps the best is yet to come.
"The new Event Horizon telescope results should be on the horizon – it should be even closer. We are really looking into the abyss here. "
SAGGITARIUS A
Like almost all galaxies, we know that there is a supermassive black hole in the heart of the Milky Way. Its gravity equates to about four million suns.
It is far. Approximately 25,000 light-years.
But it's brilliant. Interstellar gas accelerates as it approaches it. When the gas particles jostle, it creates friction – and a glow – when it swirls in an accretion disk.
The challenge is to look through this huge cloud to see the true point of no return. The horizon of events.
After 15 years of observation, astronomers have noticed a particular point in this cloud of gas that sparkles brilliantly. Sometimes it lights up about 30 times more than normal – but only for about 5 minutes.
The Max Planck Institute for Extraterrestrial Physics in Garching, Germany, follows these flashes. They managed to do it with incredible precision.
It moves in the direction of clockwise. It moves at about a third of the speed of light. And, during the three months, he drew the shape of a small circle.
So what could possibly produce such lightning?
Astronomers suggest that they could be "hot spots", magnetically heated plasma drops stretched to breaking point in the last possible position for a secure orbit. Beyond this point, everything begins irreversibly to collapse until the event horizon itself.
Beyond the horizon of events, reality itself disappears.
"We are looking at about 7.5 times more things than the black hole – the distance of the event horizon," Brown said. "In other words, if the horizon of events has a radius of 6 million km, we will see only 45 million kilometers of the black hole. This sounds great, but for comparison, the sun is only 150 million miles from the Earth. It's so spectacular that it moves at a third of the speed of light! "
It is not the superheated plasma itself that generates the flashes.
This is the gravitational lens of the black hole itself – a space-time rotation to focus some of the energy emitted by the plasma into space, like a projector.
SNARED BY GRAVITY
Things get weird around black holes. That's why astronomers are so eager to watch it.
They hope that their observations will shed light on the theories of Albert Einstein and Stephen Hawking.
Everything about black holes is infinite. And the infinite has no place.
So, in Chile, telescopes have powered a new tool called GRAVITY, everything they see from the heart of the galaxy.
As part of the network of very large telescopes managed by the European Southern Observatory, the four 9 m telescopes combine their recordings in real time, thus constituting the virtual equivalent of a 70 m diameter telescope .
Flares have been seen coming out of Sagittarius A before.
But, with this new resolution, they have been able to follow the charged plasma flashes to the point where – if it speeds up – its gravity increases to a point where it irrevocably drives it into the black hole.
This "provides the long-awaited confirmation that the object at the center of our galaxy is, as has long been assumed, a supermassive black hole," reads in a press release. ESO.
Reinhard Genze, director of the Max Planck Institute for Extraterrestrial Physics, said: "It was always a project of our dreams, but we did not dare hope it would be possible sooner."
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