The Stars That Have Never Died… Because the Universe Is Too Young

The most common star in the universe has never died. Not once. Not anywhere. Red dwarfs make up seventy percent of all stars in the Milky Way, yet not a single one is visible to the naked eye, and not a single one has ever reached the end of its life. The universe, at 13.8 billion years old, is simply too young. These small, dim stars burn so efficiently that their lifespans stretch into the trillions of years, hundreds of times longer than the current age of the cosmos. In this video, we explore how one structural difference, full convective mixing, lets red dwarfs burn nearly all their fuel while the Sun wastes ninety percent of its own. We trace what models predict for their eventual death: a slow transformation into a blue dwarf, a type of star that has never existed anywhere because the universe hasn't been around long enough to produce one. And we look at what the far future holds, a dark, quiet cosmos where the only stars still shining are the smallest, most patient ones the universe ever made. Sources: Laughlin, G., Bodenheimer, P. & Adams, F.C. (1997). "The End of the Main Sequence." The Astrophysical Journal, 482(1), 420-432. https://doi.org/10.1086/304125 Adams, F.C. & Laughlin, G. (1997). "A dying universe: the long-term fate and evolution of astrophysical objects." Reviews of Modern Physics, 69(2), 337-372. https://doi.org/10.1103/RevModPhys.69... Gillon, M., Triaud, A.H.M.J., Demory, B.-O. et al. (2017). "Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1." Nature, 542(7642), 456-460. https://doi.org/10.1038/nature21360 Chabrier, G. & Baraffe, I. (1997). "Structure and evolution of low-mass stars." Astronomy & Astrophysics, 327, 1039-1053. #RedDwarfs #Stars #Space #Astronomy #Universe #StellarEvolution #ProximaCentauri