Observations using the James Webb Space Telescope (JWST) reveal that Sagittarius A* (Sgr A*), the supermassive black hole at the centre of the Milky Way, is constantly emitting flares like a dragon of varying intensity and duration. The study was published in The Astrophysical Journal Letters on 18 February 2025.
Researchers recorded faint flickers lasting only seconds, along with more intense daily flares. Some weaker flares were observed to persist for months.
Using JWST’s near-infrared camera (NIRCam), scientists monitored Sgr A* over multiple eight-to-ten-hour sessions across 2023 and 2024, documenting changes in each observation.
The flares originate from the black hole’s accretion disk, a dense ring of gas and dust. Observations suggest bursts occurring up to six times a day, with additional smaller flares.
Researchers propose that weaker flares are small disturbances in the accretion disk, while larger ones may result from magnetic reconnection, a process that accelerates charged particles and generates radiation.
Scientists have submitted a request for 24-hour uninterrupted JWST observations to better understand flare patterns and determine whether they follow a periodic cycle or occur randomly.