“Fomalhaut is a strange case. It's going through an unusually long puberty. The star is 440 million years old. That's still very young, but it's surprising that it's holding onto part of its protoplanetary disk for so long.”
PBS Space Time · Ideas & Essays · November 2026
Context
O'Dowd had just explained how planets form from a disk of dust and gas around a young star, and how our own solar system's disk cleared within tens of millions of years. He then turns to why Fomalhaut's ring is odd.
Transcript
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Today's episode is supported by Curiosity Stream. It's well known that after his defeat at the end of the Third Age, the dark lord Sauron fled Mordor into the sky and traveled about 25 light years towards the constellation Pisces Astrinus. We still see his terrible flaming eye gazing down at us, biding his time. The incredible Hubble Space Telescope picture of the star Fomalort does excite the imagination, doesn't it? Today, I want to set your mind at ease. This isn't really the eye of Sauron. Probably. Fomalort is an A-type star, about twice as massive and much hotter and brighter than the Sun. At only 25 light years away, it's the 18th brightest star on the sky. But even as a non-dark lord, it's a fascinating object. Let's look at some pictures. That dot in the middle marks the location of the star. But you can't actually see Fomalot in this picture because the mask was placed directly in front of it for the picture. Such a mask is called a coronagraph, and its purpose is to block the bright light of…
This episode is brought to you by Google Chrome. You think you know a browser, but Gemini and Chrome, that's new. It can help you with practically anything on the web, like restoring a vintage motorcycle from a 50-page restoration blog, or finally break down that long article you've had open for…
Biding the dust into a well-defined tract. Just like Strider guiding a pack of hobbits through the wild. Every grain of dust in the Fomalort system is in orbit around the star. The closer an object orbits to a given star, the faster it moves through space. The farther out it orbits, the slower it…
This episode is brought to you by Google Chrome. You think you know a browser, but Gemini and Chrome, that's new. They can help you with practically anything on the web, like restoring a vintage motorcycle from a 50-page restoration block, or finally break down that long article you've had open for…
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