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(Archives) Illustration of a black hole – NASA / ESA / HUBBLE / AFP / Archives
Can we finally see a black hole? An international collaboration of radio telescopes and observatories, the Project Event Horizon Telescope (EHT), which aims to capture the first image of one of these "monsters" of space, announces "a result without previous "for next Wednesday.
The mystery is about everything that will be revealed, but the mobilization is exceptional: "Six major press conferences will take place simultaneously in the world: Belgium (Brussels), Chile (Santiago), China (Shanghai), Japan (Tokyo) Taipei Taiwan) and the United States (Washington), "says the European Southern Observatory (ESO).
In April 2017, eight telescopes in different parts of the world simultaneously revealed two black holes: Sagittarius A * in the center of the Milky Way and its congeners in the center of the M87 galaxy. The goal: to try to get an image.
For although we talk about black holes since the eighteenth century, no telescope has allowed to "see" one.
"We think that what we call a black hole exists in the universe, even though we have never seen one," said Paul McNamara, a senior scientist at AFP. European Space Agency (ESA) at LISA Pathfinder.
Black holes are celestial bodies that have an extremely large mbad in a very small volume. As if the sun was only 6 kilometers in diameter or the Earth was compressed to the size of a finger.
They are so mbadive that nothing escapes them, neither matter nor light, whatever their length of wave. The other side of the coin is that they are invisible.
But science is progressing. "The main recent developments concern the observation," said AFP British astrophysicist Martin Rees, former partner of Stephen Hawking of the University of Cambridge, last month.
– Giant virtual telescope –
The Horizon Telescope of Events, when it manages to create a virtual telescope about the size of Earth about 10,000 kilometers in diameter, is a good illustration of the progress of radio astronomy.
With an undeniable difference, because the larger the telescope, the more you can see the details.
"Instead of building a giant telescope (which might sink under its own weight), several observatories are combined as if it were small fragments of a giant mirror," said Michael Bremer. , astronomer at the Institute of millimeter radio astronomy (IRAM) and responsible for EHT observations of European telescopes.
With the IRAM telescope in Sierra Nevada (Spain), the powerful ALMA radio telescope in Chile and structures in Hawaii (USA) and Antarctica, the Event Horizon telescope covers a large part of the planet.
With their multiple observations, astronomers seek to identify the immediate environment of a black hole.
According to the theory, when matter is absorbed by the monster, it emits a light. The EHT project, capable of capturing the millimeter waves emitted by the environment of the black hole, aimed to define the outline of the celestial body, called the horizon of events.
Sagittarius A *, the first of two project targets, is located 26,000 light-years away from Earth. Its mbad is four million times that of the sun.
His fellow M87 galaxy is "one of the most mbadive black holes known, 6 billion times more than our Sun and 1,500 times more than Sgr A *," says EHT. It is located 50 million light-years away from Earth, "proximity to the cosmic scale, but 2000 times farther than Sgr A *," he adds.
lc-mh / alu / ra / erl / mr
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