Researched
First Black Hole Images (EHT)
The Event Horizon Telescope imaged the shadow of the black hole in galaxy M87 (released 10 April 2019) and of the Milky Way's Sagittarius A* (12 May 2022).
Open in the interactive tree →Radio telescopes on several continents were linked into one instrument, and the images of both black holes use data from April 2017. The ring around M87*, in a galaxy 55 million light-years away, matched the shadow size predicted by Einstein's theory and gave a mass of 6.5 ± 0.7 billion suns. Polarised images followed (Sagittarius A*, 22 March 2024), and on 18 September 2025 the collaboration reported that the magnetic-field pattern around M87* reversed between 2017 and 2021 while the ring size stayed the same.
Prerequisites
- Theory of Relativity1905
- Radio astronomy1933EHT links radio telescopes by interferometry
- Black Holes (Cygnus X-1)1971-72Observations of black hole candidates led to imaging their shadows
- Black Hole Thermodynamics1974Black-hole theory built by Hawking and others defines what the EHT images test