Dr. Becky

How quasars got their name

When quasars were first discovered, we didn’t really know what they were and called them “Quasi-stellar object” and that was smushed together to make quasar - sometimes you’ll see that written as “QSO” So “quasi-stellar” meant they kind of looked like stars in images, but when you took a spectrum it didn’t look anything like what we see for stars. And eventually thanks to the launch of Hubble in the 1990s, that we realised what quasars are, because it was powerful enough to resolve the galaxies that the quasars were in the centre of. Before that, the quasar was bright enough that it drowned out the entire galaxy of stars. That’s because quasars are growing supermassive black holes, the matter that’s spiralling around it will eventually get trapped inside the black hole and make it heavier. And that material is moving so fast that it gets incredibly hot and it glows in visible, UV, infrared and X-ray light. Radiation essentially, that if you’re anywhere near will be absolutely fatal. The brightest is ultra-luminous quasar J0100+2802, a black hole twelve billion times heavier than the Sun, growing heavier by 1 suns worth of matter every single day. Because it's growing so fast the gas around it is lit up brighter than 400 trillion Suns combined. Thankfully J0100+2802 is 12.8 billion light years away, and nowhere near any of us. But it still makes my list of the 5 most dangerous places in the Universe. I’ll link that video down below if you want to check it out, and you should subscribe if you want to hear about more cool, dangerous places in the Universe. Video filmed on a Sony ⍺7 IV Video edited by Martino Gasparrini: [email protected] 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!): http://lnk.to/DrBecky --- 👕 My merch, including JWST designs, are available here (with worldwide shipping!): https://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. http://drbecky.uk.com