If you thought the first image of a black hole in the distant galaxy M87 was something special two years ago, a newly released video that brings together the work of 19 observers will throw you off. In 2019, the Event Horizon Telescope (EHT) captured the 25 billion-mile-wide black hole for the first time, but don’t let the name fool you by imagining a telescope with the eye of an astronomer pressed into the viewfinder.
The M87 – or Messier 87 – is, at least in astronomical terms, close. About 55 million light-years from Earth, it is one of the most massive galaxies in the local universe and was first identified by Charles Messier in 1781.
However, the black hole in its center kept its mysteries much longer. An example of a supermassive black hole forced astronomers to think sideways when they wanted to capture an image of it: after all, black holes by definition capture light. EHT collected data from eight different telescopes and gathered this information to create an image of the bright gas surrounding the black ink maw in its center, the gravitational bending causing a shadow.
The image first appeared in 2019, but now EHT offers more tools and more details again. “I knew that the first direct image of a black hole would be revolutionary,” said Kazuhiro Hada of the National Astronomical Observatory in Japan, co-author of a new study published in The Astrophysical Journal Letters to describe the new data. “But to make the most of this remarkable image, we need to know all we can about the behavior of the black hole at that time, observing the entire electromagnetic spectrum.”
This time, 19 observatories – including five operated by NASA – were exploited to provide an unprecedented tour of the M87 at various wavelengths of light. It is based on the fact that the gravitational attraction of the black hole can create jets of particles that travel at almost the speed of light, across the entire electromagnetic spectrum. These jets are scattered throughout the universe, covering radio waves with visible light up to gamma rays, with different sets collected by the 19 different instruments.
The video starts with the original EHT image, then turns into spirals through the radio telescope matrix, through visible and then ultraviolet light and then through X-rays. Finally, there is data from the gamma-ray telescopes on the ground, together with the Fermi NASA in space.
It took 760 scientists and engineers from 200 institutions and, during March and April 2017, to compose the vast data set. Nor is it just for entertainment, with the potential to unlock new scientific discoveries.
“For example,” explains NASA, “scientists intend to use this data to improve tests of Einstein’s theory of general relativity. Currently, the main obstacles to these tests are the uncertainties about the material that rotates around the black hole and is thrown into jets, especially the properties that determine the emitted light. ”
In the meantime, it could help us understand “cosmic rays”, how they are formed, and the potential impact they have on the rest of the universe. “These jets manage to transport the energy released by the black hole to larger scales than the host galaxy, like a huge power cord,” says Sera Markoff, of the University of Amsterdam and co-author of the study. “Our results will help us calculate the amount of energy transported and the effect of black hole jets on its environment.”