The supermassive black hole in the heart of our galaxy appears busier than ever. New observations from NASA’s James Webb Space Telescope (JWST) reveal that this black hole — known as Sagittarius A* — is giving off bursts of light every day and shows no signs of slowing down.
In an observational study published in The Astrophysical Journal Letters, researchers looked at what might be causing these events.
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Peering into the Heart of Our Galaxy with the James Webb Space Telescope
Sagittarius A* sits in the center of our Milky Way, surrounded by a swirling disk of gas and dust called an accretion disk. By focusing JWST’s near-infrared camera on the black hole for nearly 48 hours in total, a team of astrophysicists led by Northwestern University obtained a close-up view of this active environment. They found the black hole’s accretion disk emits a steady stream of glowing flares, big and small, with no downtime in between.
The team took repeated measurements throughout 2023 and 2024, capturing both bright eruptions and faint flickers. These flares sometimes popped up for just a few seconds or kept glowing for months. This constant activity was unexpected, leading researchers to compare the black hole’s behaviour to “random fireworks” rather than a predictable sequence of events.
Daily Flares and Unpredictable Flickers: Sagittarius A* in Action
From their data, scientists believe multiple processes could explain Sagittarius A*’s dynamic flaring patterns. Minor turbulence within the accretion disk can compress clouds of hot, charged gas (plasma), creating small bursts of light. Larger flares, however, may come from a sudden reconnection of magnetic fields, which unleashes streams of energetic particles traveling at speeds close to the speed of light.
Interesting article: Could a human enter a black hole to study it? (Universal-Sci)
Interestingly, when the team measured two separate infrared wavelengths, they saw a slight delay: short-wavelength flares peaked just seconds before the longer-wavelength light. This clue suggests the particles might lose energy quickly at shorter wavelengths before emitting the longer-wavelength radiation.
Looking Ahead: Unraveling the Mysteries of Milky Way’s Supermassive Black Hole
Armed with these fresh insights, the researchers plan to continue observing Sagittarius A* in even longer, uninterrupted sessions to reduce background noise. By doing so, they aim to see if the flares repeat in a pattern or if they truly appear at random.
The findings promise to help scientists better understand black holes and their interactions with surrounding matter. Learning more about how our galaxy’s central black hole evolves could offer a closer look at processes shaping the Milky Way — and likely many other galaxies across the universe.
Sources, further reading and related articles:
Closest Ever Black Hole to Earth Discovered, Unveiling a Missing Link - (Universal-Sci)
Could a human enter a black hole to study it? - (Universal-Sci)
Black holes aren’t totally black, and other insights from Stephen Hawking’s groundbreaking work - (Universal-Sci)
Largest Black Hole Jets Ever Discovered, Spanning the Length of 140 Milky Way Galaxies - (Universal-Sci)
Non-stop variability of Sgr A* using JWST at 2.1 and 4.8 micron wavelengths: Evidence for distinct populations of faint and bright variable emission - (The Astrophysical Journal Letters)
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