Betelgeuse: When This Giant Star Explodes, You’ll See It in Daylight

There is a red star in Orion’s shoulder that will one day explode. Its name is Betelgeuse. It is a red supergiant roughly six hundred light-years away, already near the end of its life. When it finally dies, the explosion may become one of the most extraordinary sky events human beings have ever witnessed: a new point of light bright enough to cast shadows at night, and possibly visible even in daylight. But the strangest part is this: if you ever see Betelgeuse explode, you won’t be watching it die in real time. The star will already have died centuries earlier. What reaches us will be old light, crossing the dark for hundreds of years before finally arriving in our sky. This film follows Betelgeuse from the outside in: the red star in Orion, the Great Dimming of 2019–2020, the unstable surface of a red supergiant, the final nuclear burning stages inside its core, the formation of iron, the collapse, the stalled shockwave, the neutrinos that escape first, and the light that would eventually reach Earth. A story about a dying star. And the old light we keep mistaking for the present. THE SCIENCE: • Betelgeuse as a red supergiant in Orion. • Why its size is difficult to imagine. • The 2019–2020 Great Dimming and the dust / surface mass ejection explanation. • The giant convection cells on red supergiant surfaces. • How massive stars burn hydrogen, helium, carbon, neon, oxygen, and silicon. • Why iron ends the chain of useful fusion. • How core-collapse supernovae begin. • Why the shockwave can stall. • How neutrinos may help revive the explosion. • Why neutrinos escape before the light. • How SNEWS, the SuperNova Early Warning System, is designed to detect a Galactic supernova before visible light arrives. • What Betelgeuse might look like from Earth when its light finally reaches us. • Why the sky is always showing us the past. Note: Betelgeuse is not expected to explode imminently. The timing is uncertain, and it may have tens of thousands of years left. This episode uses cinematic language to explore what would happen when it finally does. — Atta, The Quiet Observatory CHAPTERS: 00:00 — A Star That Will Explode 02:37 — Step One: The Star That Is Already Dying 05:47 — Step Two: The Clock That Is Speeding Up 08:29 — Step Three: Iron, the Ash That Ends Everything 10:27 — Step Four: The Collapse 14:29 — Step Five: The Ghosts That Arrive First 18:44 — Step Six: The Light Arrives 22:22 — Step Seven: What Is Left Behind 23:17 — Old Light Sources and further reading below. BETELGEUSE / RED SUPERGIANTS / GREAT DIMMING The Great Dimming of Betelgeuse: a Surface Mass Ejection and its Consequences https://arxiv.org/abs/2208.01676 A dusty veil shading Betelgeuse during its Great Dimming https://arxiv.org/abs/2201.10551 Spatially Resolved Ultraviolet Spectroscopy of the Great Dimming of Betelgeuse https://arxiv.org/abs/2008.04945 The evolutionary stage of Betelgeuse inferred from its pulsation periods https://arxiv.org/abs/2306.00287 Evolutionary Tracks for Betelgeuse https://arxiv.org/abs/1406.3143 The past and future evolution of a star like Betelgeuse https://arxiv.org/abs/1303.1339 Daylight Photometry of Bright Stars — Observations of Betelgeuse at Solar Conjunction https://arxiv.org/abs/2112.12673 CORE-COLLAPSE SUPERNOVAE / STELLAR DEATH Toward Realistic Models of Core Collapse Supernovae https://arxiv.org/abs/2205.13438 The Core-Collapse Supernova Explosion Mechanism https://arxiv.org/abs/1702.06940 The explosion mechanism of core-collapse supernovae: progress in supernova theory and experiments https://arxiv.org/abs/1501.01334 Explosion Mechanism, Neutrino Burst, and Gravitational Wave in Core-Collapse Supernovae https://arxiv.org/abs/astro-ph/0509456 Properties of Convective Oxygen and Silicon Burning Shells in Supernova Progenitors https://arxiv.org/abs/1709.00236 Inferring Explosion Properties from Type II-Plateau Supernova Light Curves https://arxiv.org/abs/1903.09114 SUPERNOVA NEUTRINOS / EARLY WARNING SNEWS 2.0: A Next-Generation SuperNova Early Warning System for Multi-messenger Astronomy https://arxiv.org/abs/2011.00035 The SNEWS 2.0 Alert Software for the Coincident Detection of Neutrinos from Core-Collapse Supernovae https://arxiv.org/abs/2406.17743 The SuperNova Early Warning System https://arxiv.org/abs/0803.0531 SNEWS: The SuperNova Early Warning System https://arxiv.org/abs/astro-ph/9911359 HISTORICAL SUPERNOVAE Supernova 1604, Kepler’s supernova, and its remnant https://arxiv.org/abs/1612.06905 A Deep Chandra Observation of Kepler’s Supernova Remnant https://arxiv.org/abs/0708.3858 ------------------------------------------------- The observatory also lives on Substack: the episodes as pure audio, quiet versions for sleep, and just the voice on its own. quietobservatory.substack.com