The EHT observed Sgr A* on multiple nights, collecting data for many hours in a row, similar to using a long exposure time on a camera. To image it, the team created the powerful EHT, which linked together eight existing radio observatories across the planet to form a single “Earth-sized” virtual telescope. Falcke, Melia, Agol 2000, Astrophysical Journal Letters 528, p17īecause the black hole is about 27,000 light-years away from Earth, it appears to us to have about the same size in the sky as a donut placed on the Moon. Picture calculated in 2000 as a prediction of the black hole image, and suggesting that it should be possible to observe a black hole using a global network of telescopes at millimetre-waves. In other words, we can do an exciting test of Einstein’s theory! He wins again!” This allows the prediction of the size of the shadow, assuming the general relativity is correct, which we can now compare with the observations. “ For me the image of Sgr A* is even more exciting than our first black hole image of M87,” said Professor Kramer.“ For Sgr A*, we already knew the mass and distance of the black hole from other measurements. The EHT team's results are being published today in a special issue of The Astrophysical Journal Letters. The new view captures light bent by the powerful gravity of the black hole, which is four million times more massive than our Sun. Left to right: Professors Michael Kramer, Luciano Rezzolla and Heino Falcke at the Effelsberg Radio Telescope.Īlthough we cannot see the event horizon of the black hole because it is completely dark, hot and glowing gas around it reveals a telltale signature: a dark central region, called a “shadow”, surrounded by a bright ring-like structure. The project, proposed in 2013 and supported with an ERC Synergy Grant from 2014 to 2020, aimed not only to produce the first-ever image of a black hole, but also “turn our Galactic Centre into a fundamental-physics laboratory to measure the fabric of space and time with unprecedented precision.’ Now these objectives have been fully accomplished. Professor Falcke together with Professors Michael Kramer from the Max Planck Institute for Radioastronomy, and Luciano Rezzolla from Goethe University Frankfurt, and their teams of postdocs and PhD students and research staff, led BlackHoleCam. This is a lifelong dream come true,’ said Heino Falcke Professor of Astroparticle Physics and Radio Astronomy at Radboud University in Nijmegen, Netherlands.
Now we can finally see that it is really there. ‘ The idea that our own Milky Way may harbour a supermassive black hole always intrigued and motivated me. This shows beyond reasonable doubt that this object known as Sagittarius A* is a black hole, and today’s image provides the first direct visual evidence of it. Scientists had previously seen stars orbiting around something invisible, ultra-compact, and very massive at the centre of the Milky Way. The new image is a long-anticipated look at the massive object that sits at the very centre of our own galaxy. The breakthrough follows the EHT collaboration’s 2019 release of the first image of a black hole, called M87*, at the centre of the more distant Messier 87 galaxy.
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