Polaris Doesn't Want to Be Measured, and It's Genuinely Baffling Scientists

The problem with Polaris, the North Star. Get a special 35% discount* on an annual digital subscription to The Economist at https://www.economist.com/Astrum *20% in the UK, Latin America, and India. Referenced article: https://www.economist.com/science-and-technology/2025/08/06/astronomers-cannot-agree-on-how-fast-the-universe-is-expanding ▀▀▀▀▀▀ For centuries, we've relied on the North Star to guide us across the Earth. A static, bright beacon in the northern sky, Polaris serves as a reliable method of navigation… or does it? This star proves far more challenging to study than it initially appears. From its distance, to its secret companions, we’re unravelling the mysteries of Polaris - mysteries that only grow stranger the closer we look. ▀▀▀▀▀▀ 0:00 The Problem with Polaris 1:04 Finding the North Star 2:08 Triple Star System 4:36 Cepheids: Standard Candles 6:34 Polaris Aa Is Weird 11:54 Are Our Models Wrong? 16:06 The Age Paradox 18:18 Polaris Won't Be the North Star Forever ▀▀▀▀▀▀ Astrum's newsletter has launched! Want to know what's happening in space? Sign up here: https://astrumspace.kit.com ▀▀▀▀▀▀ Astrum Displate Posters: https://astrumspace.info/Displates Astrum Infographic Artwork: https://electrify.art/collections/astrum Astrum Merch: https://astrum-shop.fourthwall.com/ Join us on the Astrum discord: https://discord.gg/TKw8Hpvtv8 A huge thanks to our Patreons who help make these videos possible. Sign-up here to support the channel: https://bit.ly/4aiJZNF ▀▀▀▀▀▀ Astrum Podcast on Spotify: https://open.spotify.com/show/6jPRrbq3o3dpvBb173ZTKi?si=a90d3efe3b704c83 Astrum Earth: https://youtube.com/@AstrumEarth Astrum Extra: https://www.youtube.com/@astrumextra Astrum Spanish: https://www.youtube.com/@astrumespanol Astrum Portuguese: https://www.youtube.com/channel/UChn_-OwvV63mr1yeUGvH-BQ ▀▀▀▀▀▀ References: “Origin of Strange 'Blue Straggler' Stars Pinned Down”, via space.com https://astrumspace.info/bluestraggler “Hubble Space Telescope Trigonometric Parallax of Polaris B”, via iop.org https://astrumspace.info/companionstar “Probing Polaris”, via eso.org https://astrumspace.info/probingpolaris “Finding magnetic north: an extraordinary magnetic field detection in Polaris and first results of a magnetic survey of classical Cepheids”, via ras.ac.uk https://astrumspace.info/polarismagneticnorth “Astronomers Find Spots on Surface of Polaris”, via sci.news https://astrumspace.info/sunspots “Toward Ending the Polaris Parallax Debate: A Precise Distance to Our Nearest Cepheid from Gaia DR”, via iop.org https://astrumspace.info/polarisdistance “The Period Change of the Cepheid Polaris Suggests Enhanced Mass Loss”, via iop.org https://astrumspace.info/unstablephase “The Period Changes of Polaris”, via jstor.org https://astrumspace.info/periodincrease “Precise Radial Velocities of Polaris: Detection of Amplitude Growth”, via iop.org https://astrumspace.info/Cepheidamplitude “Periods of 25 Variable Stars in the Small Magellanic Cloud”, via harvard.edu https://astrumspace.info/Cepheidrelationship ▀▀▀▀▀▀ Credits: Writer: Julia Masselos Video Editor: Nick Shishkin Researcher: Edie Abrahams Script Editor: Damaris McColgan Thumbnail Designer: Peter Sheppard Channel Manager: Georgina Brenner Production Manager: Raquel Taylor Head of Astrum: Jess Jordan Creator of Astrum: Alex McColgan With special thanks to: NASA/ESO/ESA #astrum #space #polaris #northstar