The magnetic field surrounding the supermassive black hole at the centre of the Milky Way has been observed for the first time. Astronomers using the Event Horizon Telescope (EHT) have been surprised by the orderly nature of the field, which exists in the extremely violent environment surrounding the black hole Sagittarius A*. The study could lead to a better understanding of the crucial role that the magnetic field plays in how the black hole feeds on surrounding matter.

This is the second time that the EHT has observed the magnetic field of a supermassive black hole. In 2021 it detected the field of the black hole at the centre of the galaxy Messier 87 (M87).

Supermassive black holes are believed to be surrounded by plasma that is swirling into the gravitational abyss. This creates a powerful magnetic field, which can then interact with the infalling material. This accelerating material emits copious amounts of radiation including radio waves that are polarized by the local magnetic field.