The Biggest Star Ever Found Makes Our Sun Look Tiny

Imagine a star so large that if you placed it where our Sun is, its surface would extend past the orbit of Saturn. This is Stephenson 2-18 — the largest known star in the universe. A dying red supergiant with a radius 2,150 times larger than our Sun. An object so enormous that light itself takes over 8 hours to travel around it. A cosmic monster containing the volume of 10 billion Suns, yet so diffuse that its average density is lower than Earth's atmosphere. In this video, we explore everything about the biggest star ever discovered: how large it really is, how it formed, why it's dying, and what will happen when it finally explodes. ━━━━━━━━━━━━━━━━━━━ 📚 SOURCES: Stephenson 2-18 Properties: Figer et al. (2006) — "Massive Stars in the Sgr 1806-20 Cluster" Davies et al. (2007) — "The Cool Supergiant Population of the Massive Young Star Cluster RSGC1" Humphreys & Davidson (1979) — "Studies of Luminous Stars in Nearby Galaxies" Red Supergiant Physics: Levesque et al. (2005) — "The Effective Temperature Scale of Galactic Red Supergiants" Massey et al. (2009) — "The Physical Properties of Red Supergiants" Stellar Evolution: Woosley & Heger (2007) — "Nucleosynthesis and Remnants in Massive Stars" Smartt (2009) — "Progenitors of Core-Collapse Supernovae" Size Estimates: Arroyo-Torres et al. (2013) — "The atmospheric structure and fundamental parameters of red supergiants" Wittkowski et al. (2012) — VLTI interferometric observations Betelgeuse Dimming Event: Montargès et al. (2021) — "A dusty veil shading Betelgeuse during its Great Dimming" ━━━━━━━━━━━━━━━━━━━ The largest stars don't live long. Stephenson 2-18 has already burned through most of its nuclear fuel and will explode as a supernova within the next few hundred thousand years — possibly much sooner. When it does, the atoms it has forged will scatter across the galaxy, eventually becoming part of new stars, new planets, and perhaps new life. We are made of star stuff. And stars like Stephenson 2-18 are the factories that make it possible. ━━━━━━━━━━━━━━━━━━━ #star #space #stephenson218 #astronomy #universe #supergiant #betelgeuse #supernova #cosmos #science #documentary #sun #physics #astrophysics #NASA #redsupergiant #biggeststar #uyscuti #vycma #stellarevolution