Astronomers using NASA’s James Webb Space Telescope (JWST) have taken a detailed look at the supermassive black hole at the center of our Milky Way, called Sagittarius A*. They found that the swirling disk of gas and dust around it constantly emits flares.
These flares vary in brightness and duration: some last just seconds, while others are bright eruptions happening daily, with even fainter flickers surging for months. This activity helps physicists better understand black holes and their interactions with their surroundings.
Farhad Yusef-Zadeh from Northwestern University led the research, observing Sagittarius A* multiple times in 2023 and 2024. They noticed changes each time, which is remarkable. The team used JWST’s Near Infrared Camera (NIRCam) to track these changes over 48 hours in 8-to-10-hour sessions across one year.
The observations revealed continuous “fireworks” of varying brightness and durations, with no discernible pattern. Yusef-Zadeh explained that minor disturbances in the accretion disk, similar to solar flares, likely cause short, faint flickers. In contrast, the big, bright flares are caused by magnetic reconnection events, where magnetic fields collide and release energy.
The team also discovered that events at shorter wavelengths changed brightness slightly before those at longer wavelengths, providing new clues about the processes around the black hole. One explanation is that particles lose energy faster at shorter wavelengths than longer ones.
To further investigate, Yusef-Zadeh submitted a proposal for an uninterrupted 24-hour observation of Sagittarius A*. This longer observation time would help reduce noise and reveal finer details, potentially showing whether the flares are periodic or random.
Journal Reference:
- F. Yusef-Zadeh et al., Nonstop Variability of Sgr A* Using JWST at 2.1 and 4.8 μm Wavelengths: Evidence for Distinct Populations of Faint and Bright Variable Emission, The Astrophysical Journal Letters (2025). DOI: 10.3847/2041-8213/ada88b
Source: Tech Explorist
