From Dr. Becky.
AD – To try everything Brilliant has to offer for free for a full 30 days, visit https://brilliant.org/DrBecky and you’ll also get 20% off an annual premium subscription. | The supermassive black hole at the centre of our galaxy, the Milky Way, is flickering – we know that thanks to observations taken in the past few years with the James Webb Space Telescope, JWST, which were published this month by Yusef-Zadeh and collaborators. Now just to be clear what’s been detected is not light from the black hole itself, because black holes are so dense and their gravity is so strong that not even light can escape from them. The light that has been detected is from the region around the black hole, what’ known as the accretion disk, a swirling, glowing, maelstrom of material orbiting the black hole which will eventually fall beyond the event horizon and add to the black hole’s mass. This material is accelerated to such huge speeds that it glows, so by studying that glow we can work out what is going on in in those turbulent regions around the black hole, we can study how our supermassive black hole is growing – is it smooth growth, or is there a lot of turbulence which causes the light we receive to vary and flicker? But JWST also spotted some bright flares from our supermassive black hole, so what’s causing those?
Yusef-Zadeh et al. (2025) – https://iopscience.iop.org/article/10.3847/2041-8213/ada88b
JWST proposal 1 – https://www.stsci.edu/jwst/phase2-public/2235.pdf
JWST proposal 2 – https://www.stsci.edu/jwst/phase2-public/3559.pdf
Padovani et al. (2017) – https://arxiv.org/pdf/1707.07134
Simmons, Smethurst, Lintott (2017) – https://arxiv.org/pdf/1705.10793
00:00 Introduction
02:54 How light around black holes is generated
07:14 What’s been observed with JWST
12:03 What this means for how the Milky Way’s black hole is growing
15:15 Bloopers
Video filmed on a Sony ⍺7 IV
Video edited by Martino Gasparrini: https://www.fiverr.com/mgs_editing
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👩🏽💻 I’m Dr. Becky Smethurst, an astrophysicist at the University of Oxford (Christ Church). I love making videos about science with an unnatural level of enthusiasm. I like to focus on how we know things, not just what we know. And especially, the things we still don’t know. If you’ve ever wondered about something in space and couldn’t find an answer online – you can ask me! My day job is to do research into how supermassive black holes can affect the galaxies that they live in. In particular, I look at whether the energy output from the disk of material orbiting around a growing supermassive black hole can stop a galaxy from forming stars.
