A four-person team at CSIRO, Australia’s national science agency, has independently reconstructed the image of the supermassive black hole at the center of galaxy M87 and recovered the same ring-shaped “shadow” first shown by the Event Horizon Telescope collaboration in 2019, according to a study published Nov. 11 in Nature and a CSIRO announcement.
The Event Horizon Telescope links radio telescopes around the world to mimic a single telescope the size of Earth. Its 2019 image became one of the most recognized scientific images of the modern era, CSIRO said. But because the measurements are sparse, different analyses produced divergent fine-scale features, and some outside analyses challenged the ring-like shape itself, the authors wrote in Nature. They said results are sensitive to instrument calibration, processing algorithms and imaging settings.
To reduce those effects, the team used “closure invariants,” which combine measurements from three telescopes at a time instead of the standard pairs, a method the researchers said removes atmospheric and instrumental errors. They paired it with a machine learning imaging method called GenDIReCT, trained on ordinary images such as cats, dogs and cars so that it had no prior idea what a black hole looked like, lead author Samuel Lai and project leader Nithyanandan Thyagarajan wrote in an article republished by CSIRO. They froze the method before letting it analyze the M87 data on Dec. 4, 2025, and checked the result with a second, conventional statistical technique.
The reconstruction showed a ring 42.2 microarcseconds across, give or take 1.5, consistent with a black hole of about 6.5 billion solar masses viewed roughly 20 degrees from its approaching jet, the study reported. The authors said the result matches the original image in diameter and overall orientation, with some differences in ring width and brightness along its edge. M87 lies about 55 million light-years from Earth.
“It is like standing in your backyard and trying to take a photo of a doughnut on the Moon,” Lai said in the CSIRO release. “This is the first truly independent validation of the EHT image, an important step in the scientific process.”
Laurent Loinard, director of the Event Horizon Telescope collaboration, welcomed the outside check. “It is extremely gratifying to see that GenDIReCT, an elegant, entirely independent, method, recovers the ring structure of M87* across several years, in excellent agreement with the EHT Collaboration’s published results,” he said, according to CSIRO. Thyagarajan said the technique could also be applied to medical imaging and earthquake mapping.