An article published in “The Astrophysical Journal Letters” reports the results of a study on the region of very hot plasma that surrounds a black hole called the corona. A group of researchers used detections conducted with the IXPE space telescope to obtain precise information on the corona of 12 black holes ranging from stellar-mass ones to supermassive black holes. For the first time, it was possible to observe the geometry of the corona of black holes and its relationship with the accretion disk that surrounds them. The geometry seems very similar regardless of the size of the black holes but this is still a tentative result.