Speaker 1: Welcome to brain Stuff from How Stuff Works, Hey, brain Stuff,
Speaker 1: Lauren Vogel bomb Here. Our Sun may look like an
Speaker 1: eternal miasma of incandescent plasma, but one day it will die.
Speaker 1: This may sound like a bummer, especially for anything that's
Speaker 1: living on Earth in a few billion years, but there
Speaker 1: is a bright side to the solar doom. According to
Speaker 1: research published in the journal Nature, this very month, our
Speaker 1: dead star will leave behind a shimmering legacy. It'll turn
Speaker 1: into a massive crystal. Before we start talking about supersized
Speaker 1: stellar crystals, we first need to understand how stars like
Speaker 1: our Sun live and die. The Sun is fueled by
Speaker 1: nuclear fusion. It's massive gravity crushes hydrogen atoms together in
Speaker 1: its core to create helium, and the vast quantities of
Speaker 1: energy released by these fusion processes push outward, maintaining a
Speaker 1: happy equilibrium. So long as there's plenty of hydrogen fuel
Speaker 1: feeding this process, the core remains about the same side
Speaker 1: as in temperature around fifteen million kelvin, producing energy that
Speaker 1: radiates throughout the Solar system, ultimately nurturing the evolution of
Speaker 1: life on a certain habitable planet. This hydrogen burning phase
Speaker 1: of a star's life will last of the lifetime of
Speaker 1: our Sun. The period of stellar life is known as
Speaker 1: the main sequence. We're currently about four point five billion
Speaker 1: years into our Sun's main sequence days, or approximately halfway
Speaker 1: through its life. So what happens when that hydrogen is
Speaker 1: all used up? Things start to get a little wild,
Speaker 1: to put it mildly. Without the outward pressure of the
Speaker 1: energy created by fusing hydrogen, the Sun's gravity overwhelms the core,
Speaker 1: crushing it into a smaller space and boosting its temperature tenfold.
Speaker 1: That's okay, though, the heavier helium nuclei will begin to
Speaker 1: fuse together, creating the outward pressure once again to maintain equilibrium.
Speaker 1: It's predicted that this will start happening in about five
Speaker 1: billion years, marked with a sudden outbrush of energy known
Speaker 1: as a helium flash. As the helium fuses, carbon and
Speaker 1: oxygen are formed and the temperature of the core rises
Speaker 1: yet again. Soon after, even heavier elements also begin to fuse,
Speaker 1: and the Sun on the whole will start looking a
Speaker 1: bit worse for the wear. It will begin to swell,
Speaker 1: blasting into planetary space with savage solar winds that will
Speaker 1: begin to strip away its upper layers. Though our Sun
Speaker 1: isn't massive enough to explode as a supernova, it will
Speaker 1: turn into a red giant star, possibly expanding beyond the
Speaker 1: orbit of Earth. Our planet will be toast. After the
Speaker 1: death of our star, it will leave behind whispy remains
Speaker 1: of solar plasma, creating a beautiful planetary nebula, enriched with
Speaker 1: newly formed heavy elements that will go on to create
Speaker 1: the next generation of stars and planets, And in its
Speaker 1: core will be a hot stellar remnant known as a
Speaker 1: white dwarf, a tiny dense star shimmering brightly, a testament
Speaker 1: to the Sun that used to be in its place.
Speaker 1: White dwarfs can sustain themselves for billions of years before
Speaker 1: fizzing out in dimming forever. But this isn't the end
Speaker 1: of the story. Using observations by the European GUIA mission,
Speaker 1: which is currently making precision measurements of stars throughout our galaxy,
Speaker 1: researchers at the University of Warwick in the UK have
Speaker 1: stumbled on a white dwarf secret that has remained hidden
Speaker 1: until now. Soon after forming, white dwarfs are extremely hot,
Speaker 1: radiating the intense energy that was once held in the
Speaker 1: core of the main sequence star that came before them.
Speaker 1: Over billions of years. After forming, white dwarves slowly cool
Speaker 1: and at a certain point the oxygen and carbon they
Speaker 1: contain will go through a phase transition akin to liquid
Speaker 1: water freezing and turning into solid ice, only at much
Speaker 1: more extreme temperatures and pressures, and they'll solidify to form
Speaker 1: a huge crystal. Pierre Emmanuel Tremblay, from the University of
Speaker 1: Warwick's Department of Physics and leader of the study, said
Speaker 1: in a press release. All white dwarves will crystallize at
Speaker 1: some point in their evolution, although more massive white dwarfs
Speaker 1: go through the process sooner. This means that billions of
Speaker 1: white dwarfs in our galaxy have already completed the process
Speaker 1: and are essentially crystal spheres in the sky. The sum
Speaker 1: itself will become a crystal white dwarf in about ten
Speaker 1: billion years. Tremblay's team analyzed the Gaia observations to measure
Speaker 1: the luminosities and colors of fifteen thousand white dwarves within
Speaker 1: three d light years of Earth. What they found was
Speaker 1: an excess in the population of stars of specific colors
Speaker 1: and brightness. They realized that this group of stars represented
Speaker 1: a similar phase instellar evolution where the conditions are right
Speaker 1: for this phase transition to occur, causing a delay in cooling,
Speaker 1: thus slowing down the aging process. The researchers found that
Speaker 1: some of these stars had extended their lifespan by up
Speaker 1: to two billion years. Tremblay said in the statement, this
Speaker 1: is the first direct evidence that white dwarfs crystallize or
Speaker 1: transition from liquid to solid. It was predicted fifty years
Speaker 1: ago that we should observe a pile up in the
Speaker 1: number of white dwarves at certain luminosities and colors due
Speaker 1: to crystallization, and only now has this been observed. Stalized
Speaker 1: white dwarfs aren't just a stellar curiosity. Their quantum makeup
Speaker 1: is unlike anything we can recreate in the laboratory. As
Speaker 1: the white star material crystallizes, its material becomes ordered on
Speaker 1: a quantum level nuclei aligning themselves in a complex lattice
Speaker 1: with a metallic oxygen core and an outer layer enriched
Speaker 1: with carbon. So it turns out that after stars like
Speaker 1: our sun die, their stories aren't over all. White dwarfs
Speaker 1: will go through this crystallization process, littering the galaxy with
Speaker 1: massive diamond like stellar remnants. Today's episode was written by
Speaker 1: Ian O'Neil and produced by Tyler Claying for iHeart Media
Speaker 1: and How Stuff Works. For more on this and lots
Speaker 1: of other shining topics, visit our home planet, how stuff
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