“Imagine that you are trying to take a picture of an orange from the Earth, which lies on the moon,” — about so described the shooting of a black hole member of an international group of researchers, who on April 10 published the first in the history of the photo of a black hole.
The project, called the Event Horizon Telescope ,used eight radio telescopes located on three continents to photograph a black hole in the center of the galaxy Messier 87 (M87), in the constellation Virgo at a distance of about 55 million light years from Earth.
This black hole is considered one of the heaviest among those known to scientists, its mass exceeds the mass of the Sun in 6,5 billion times, astronomers jokingly call it “monster” and “champion in heavy weight”. What is the importance of this photo, figured Gromadske.
What scientists saw
To be precise, scientists were able to photograph not the black hole itself, but its “shadow” — how the hole looks against the background of a disk of bright and hot matter that surrounds it. This matter consists of gas. But the black hole itself is a part of space-time, which, by its nature, can not be seen: it has such a powerful force of gravity that it can not leave any object, even light. In a word, the black hole tightens everything that gets into it, its border — “horizon of events”, a point of no return.
Direct observations of the black hole continued for several days in April 2017. At the same time astrophysicists were lucky: in all parts of the planet where the Observatory was good weather.
The project participants originally planned to get an image of a supermassive black hole in the core of the milky Way. This black hole called “Sagittarius A*”, relatively small: its mass exceeds the solar only 4 million times. However, the team of scientists decided to go further and explore the black hole in the galaxy M87, because it is one of the largest and most closely located to the Earth. In addition, it was much easier to watch it than ” Sagittarius A*”.
Photos of the black hole were not obtained using an optical telescope, but thanks to interferometry — a process that combines simultaneous observation data from several radio telescopes. Astronomers have attracted six observatories in Mexico, the United States (Arizona and Hawaii), Chile and Spain, and sent eight powerful radio telescopes to the center of the galaxy M87. The data collected at the same time was investigated, then combined and received the long-awaited image.
Presentation of a photo of a black hole located in the center of the M87 galaxy during a press conference of the European research Council in Brussels, Belgium, April 10, 2019
Ahead of time
As explained by Paul Hertz, Director of astrophysics at NASA headquarters in Washington, a few years ago, scientists believed that for this study they will have to build a very large space telescope.
“But thanks to the fact that radio telescopes around the world worked together as one tool, the EHT team achieved this a decade earlier,” the scientist explained.
Einstein was right.
Published by scientists image of a black hole actually confirms the theory of gravity and the General theory of relativity, proposed by albert Einstein in 1915: it assumed the existence of black holes. About this Gromadsky told Bogdan Gnatik, Ukrainian scientist-astrophysicist, doctor of physical and mathematical Sciences, researcher of the Astronomical Observatory of the KNU named after Taras Shevchenko.
Black holes, until recently, existed as a hypothetical object. Only in the last 10-15 years, scientists-astrophysicists allowed themselves to declare their existence, because they proved it experimentally. After all, a black hole is an object, the presence of which can not be confirmed “materially”.
For example, opening a new planet, you can run a satellite on it, take soil samples and deliver to Earth. With a black hole, this can not be done, explains Gnatik: this is part of space-time, from which signals do not reach us. We can only receive a signal from the vicinity of the black hole — the so-called event horizon, which, in fact, scientists have done.
“For the first time we were able to look so close to the horizon of events, in the so-called surface of the black hole, and again confirm that Einstein’s General theory of relativity is fair, such objects are, and their properties really correspond to the characteristics that the General theory of relativity predicts. It turns out that Einstein’s theory withstands all tests and remains correct,”
the astrophysicist explained.
Is it the visual image that matters?
No. As the scientist explained, this discovery did not bring something “qualitatively new”. After all, scientists have previously modeled the appearance and structure of black holes, and now only confirmed the previous simulation.
“The photo really showed us what we have. Roughly speaking, you now took the best microscope and saw in more detail, say, a cell,” the scientist said.
The most detailed image of the black hole in popular culture is the image of the black hole “Gargantua”, which is depicted in the Hollywood film “interstellar”. For its visualization was responsible American astrophysicist Kip Thorne, who received the Nobel prize for the discovery of gravitational waves.