Uploaded June 2026 | Updated September 2026, 2 weeks ago
So the idea is all these pieces of the puzzle of little red dots are coming from the fact we’re seeing reprocessed light emitted from matter glowing as it swirls around the black hole.
So this is the hypothesis that has emerged over the past few years, it’s annoyingly known as the “black hole star” model, because it’s represented as BH* in research papers, in the same way the Milky Way’s supermassive black hole is known as “sag a*” - I know it’s incredibly confusing because quite literally nothing to do with stars. But, point is, we need to test this black hole buried in dense gas hypothesis.
So that’s what Kokorev and collaborators were trying to do when they observed the little red dot known as GLIMPSE-17775 using the NIRspec instrument on JWST for 20 hours to try and collect as much light as possible. It’s around 11 and a half billion light years away so we’re seeing this galaxy as it was when the Universe was just 2 billion years old.
And the spectrum they got is so incredibly detailed, they spotted over 40 emission and absorption features, so these spikes and dips that are the glow of specific elements like oxygen and silicon and hydrogen that each happen at unique wavelengths of light. Just to put this into context, the other spectra we have of LRDs have been a lot noisier, and have detected a handful of these features at best.
And so because of this, there’s 4 big things that this spectrum reveals.
Video filmed on a Sony ⍺7 IV
Video edited by Martino Gasparrini: martino.freelance@gmail.com
Video produced by Marina Hui & Dr Becky Smethurst
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📚 My book, "A Brief History of Black Holes", out NOW in hardback, paperback, e-book and audiobook (which I narrated myself!): lnk.to/DrBecky
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👕 My merch, including JWST designs, are available here (with worldwide shipping!): dr-becky.teemill.com
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🎧 Royal Astronomical Society Podcast that I co-host: podfollow.com/supermassive
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🔔 Don't forget to subscribe and click the little bell icon to be notified when I post a new video!
---
👩🏽💻 I'm Dr. Becky Smethurst, an astrophysicist at the University of Oxford. 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.
drbecky.uk.com
So the idea is all these pieces of the puzzle of little red dots are coming from the fact we’re seeing reprocessed light emitted from matter glowing as it swirls around the black hole.
So this is the hypothesis that has emerged over the past few years, it’s annoyingly known as the “black hole star” model, because it’s represented as BH* in research papers, in the same way the Milky Way’s supermassive black hole is known as “sag a*” - I know it’s incredibly confusing because quite literally nothing to do with stars. But, point is, we need to test this black hole buried in dense gas hypothesis.
So that’s what Kokorev and collaborators were trying to do when they observed the little red dot known as GLIMPSE-17775 using the NIRspec instrument on JWST for 20 hours to try and collect as much light as possible. It’s around 11 and a half billion light years away so we’re seeing this galaxy as it was when the Universe was just 2 billion years old.
And the spectrum they got is so incredibly detailed, they spotted over 40 emission and absorption features, so these spikes and dips that are the glow of specific elements like oxygen and silicon and hydrogen that each happen at unique wavelengths of light. Just to put this into context, the other spectra we have of LRDs have been a lot noisier, and have detected a handful of these features at best.
And so because of this, there’s 4 big things that this spectrum reveals.
Video filmed on a Sony ⍺7 IV
Video edited by Martino Gasparrini: martino.freelance@gmail.com
Video produced by Marina Hui & Dr Becky Smethurst
---
📚 My book, "A Brief History of Black Holes", out NOW in hardback, paperback, e-book and audiobook (which I narrated myself!): lnk.to/DrBecky
---
👕 My merch, including JWST designs, are available here (with worldwide shipping!): dr-becky.teemill.com
---
🎧 Royal Astronomical Society Podcast that I co-host: podfollow.com/supermassive
---
🔔 Don't forget to subscribe and click the little bell icon to be notified when I post a new video!
---
👩🏽💻 I'm Dr. Becky Smethurst, an astrophysicist at the University of Oxford. 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.
drbecky.uk.com
