A black hole has been photographed for the first time. Back in 2016 gravitational waves demonstrated the existence of these mysterious cosmic objects. Today the first direct evidence arrives and the image that bears witness to it is that of the black hole M 87 located in the center of the Virgo galaxy, about 55 million light years from us. This has been possible thanks to the international Event Horizon Telescope (EHT) project funded by the European Commission.
In the photo the shadow of a black hole with the mass of 6 billion Suns
It has been revealed by its shadow, which appears as a sort of reddish ring, the black hole in the center of the M87 galaxy with the mass of six and a half billion that of our Sun. “What we have seen is the shadow of a black hole”, Luciano Rezzolla, director of the Institute of Theoretical Physics of Frankfurt and member of the scientific committee of the collaboration EHT (Event Horizon Telescope) told.
“In the supermassive black holes that are in the center of the galaxies, the matter that is attracted heats up and, falling into the black hole, emits light, part of which can be observed with radio telescopes. In these physical conditions, in fact, it is possible to reveal the so-called ‘in the shadow’ zone, that is, that region of ‘absence of light'”, he added, referring to the boundary that separates a black hole from space surrounding it. This is a mathematical boundary where the force of gravity is so strong that nothing can escape, not even light.
“With the EHT telescopes we have finally reached a resolution higher enough to look at a scale of the event horizon,” he added. “From the inside of this surface – Rezzolla explained – no information can be exchanged with the outside. For this reason black holes are important in physics: their event horizon is in fact an insurmountable limit to our ability to explore the universe”. Since the event horizon absorbs all light, he continued, “by definition an event horizon cannot be seen directly. However, it is theoretically possible to predict how the plasma region that is next to it would look like. This is what we have done and the excellent connection between theory and observations has convinced us that this is a black hole as predicted by Einstein “.
The first page of an incredible book is open
The great novelty of the first photograph of a black hole is that invisible cosmic objects by definition for the first time can be seen and studied directly. “Now we can finally observe them,” told Rezzolla. Today the “first page of a book in which it is possible to make more and more accurate observations of these objects, provided a century ago by Albert Einstein” opens.
The announcement in 6 articles and press conference worldwide
Published in six articles in a special issue of Astrophysical Journal Letters, the result was announced simultaneously in six press conferences. The European Research Council (ERC) and the Event Horizon Telescope (EHT) project presented it in Brussels, in the presence of the European Commissioner for Research, Science and Innovation Carlos Moedas; the other five press conferences were organized in Santiago de Chile, Shanghai, Tokyo, Taipei and Washington.
Since 2014, the ERC has financed the EHT project with € 14 million. The research has been coordinated by Luciano Rezzolla, Heino Falcke, of Radboud University Nijmegen, and Micheal Kramer, of the Royal Astronomical Society. The revolutionary image was captured by the network of eight radio telescopes that is part of the EHT collaboration, set up precisely to be able to capture the most coveted photo of astrophysics.