Speaker 1: Welcome to Brainstuff, a production of iHeartRadio, Hey brain Stuff,
Speaker 1: Lauren Vogelbomb. Here humans are born, then we grow and die.
Speaker 1: Our life cycles are basically the same as those of
Speaker 1: the massive stars twinkling in the night sky. If we
Speaker 1: exploded in a blaze of glory at the end of
Speaker 1: our time when the cosmosis, most colossal stars go out
Speaker 1: with a bang. The immense interstellar explosion is known as
Speaker 1: a supernova, while smaller stars simply fizzle out. The death
Speaker 1: of an astronomical heavyweight is a showstopper. It spent its
Speaker 1: life cannibalizing its own inerds for fuel and sometimes the
Speaker 1: intererds of a solar neighbor. When there is nothing left
Speaker 1: for it to consume, it collapses in on itself and
Speaker 1: then explodes outward and a depth knell that outshines other
Speaker 1: huge stars and sometimes entire galaxies for days, weeks, or
Speaker 1: even months. Some are so bright that they can be
Speaker 1: seen with a simple set of binoculars. A supernova should
Speaker 1: statistically detonate once every fifty years or so in a
Speaker 1: galaxy the size of our Milky Way, So how do
Speaker 1: you spot one? Identifying a new point of light as
Speaker 1: a supernova as opposed to a high flying aircraft or
Speaker 1: a comet, may be easier than you think. The stars
Speaker 1: about to go supernova change color from red to blue
Speaker 1: due to their increasing temperatures, and supernova maintain some blue
Speaker 1: color due to the Doppler effect. The light from their
Speaker 1: explosions moves towards us so fast that it appears blue plus.
Speaker 1: Unlike a comet or commercial airplane, a supernova won't waver
Speaker 1: from its position. But how do stars self destruct so spectacularly?
Speaker 1: Let's talk about a giant stars life cycle. A giant
Speaker 1: stars starts out when gas and dust buckle under an
Speaker 1: assertive gravitational pull to form a baby star. As the
Speaker 1: material at the center of a fledgling star heats, it
Speaker 1: attracts more interstellar gas and dust. This growth phase can
Speaker 1: take up to fifty million years, followed by another ten
Speaker 1: billion years of shiny adulthood. Stars are fueled by the
Speaker 1: nuclear fusion of hydrogen into the slightly denser and heavier
Speaker 1: element helium. The fusion takes place in the star's core,
Speaker 1: and the energy it produces flows outward, creating the star's
Speaker 1: observable glow and preventing the heavy core from collapsing in
Speaker 1: on itself. When a star starts running out of hydrogen
Speaker 1: to fuse into helium, it's the beginning of the end.
Speaker 1: With less energy radiating outward, the core begins to collapse,
Speaker 1: causing its temperature to spike. Hydrogen fusion continues only in
Speaker 1: the star's outer layers, which causes it to expand it
Speaker 1: becomes a red giant. A red giant will lose its
Speaker 1: outer layers, either by consuming them or releasing them into
Speaker 1: space to become a white dwarf. A white dwarf with
Speaker 1: enough mass will eventually go supernova. Its core will collapse,
Speaker 1: resulting in an explosion that can't compare to any we
Speaker 1: might experience on Earth, unless we were to bundle a
Speaker 1: few Octilian nuclear warheads and detonate them all at the
Speaker 1: same time. Our own Sun isn't big enough to go
Speaker 1: out with such a bang, but stars that are are
Speaker 1: separated into two supernova classes, type one and type two.
Speaker 1: Astronomers learn a lot about stars from the colors of
Speaker 1: life that they emit. Using a device called a spectrograph,
Speaker 1: they can get a clear picture of exactly what elements
Speaker 1: are burning inside a star. In the nineteen forties, astronomers
Speaker 1: noticed that some supernova type one do not contain hydrogen,
Speaker 1: but the others do. Those are type two. In the
Speaker 1: nineteen eighties, as observational technology improved, scientists further divided type
Speaker 1: one supernova into three subcategories, Type one A, which contains
Speaker 1: silicon in their spectra, Type one B, which contain helium,
Speaker 1: and type one C, which contain neither. The stars lose
Speaker 1: elements when stellar winds rip their outer layers away long
Speaker 1: before they go supernova. A Type one A supernova work
Speaker 1: differently than all the other types. A Type one A
Speaker 1: supernova results from a white dwarf that's part of a
Speaker 1: binary system, that is, one that shares an orbit with
Speaker 1: another star and was about twice the size of our
Speaker 1: Sun during its life. The white dwarf's mass allows it
Speaker 1: to fuse elements slightly heavier than hydrogen, so it has
Speaker 1: a stable core of carbon and oxygen. Left to its
Speaker 1: own devices, this white dwarf would eventually decay into a
Speaker 1: black dwarf, but since it's not alone, it has access
Speaker 1: to resources that other stars don't. The more massive of
Speaker 1: the two stars acts like an opportunistic sibling, using its
Speaker 1: gravitational pull to steal matter from the other star. This
Speaker 1: gluttonous star grows until it exceeds what's called the Chindra
Speaker 1: Shaykhar limit, after the guy who discovered it. It's a
Speaker 1: mass of one point four times that of our self,
Speaker 1: otherwise known as one point four solar masses. At this size,
Speaker 1: the white dwarf suddenly has enough heat and pressure in
Speaker 1: its core to fuse carbon, and all of that carbon
Speaker 1: fuses at once, like a thermonuclear bomb going off, blowing
Speaker 1: the star to bits. It leaves behind a gaseous remnant
Speaker 1: that's symmetrical in shape and contains a great deal of
Speaker 1: iron created in the heat of the explosion. Because type
Speaker 1: one A supernovae all explode at the same point in
Speaker 1: their stellar deaths, they all peak at almost exactly the
Speaker 1: same brightness. It's so consistent that type one A supernova
Speaker 1: are also called standard candles. Once astronomers find one in
Speaker 1: a region of space, they can use it as a
Speaker 1: baseline with which to compare and learn about other objects
Speaker 1: around it. Type one, B, one C, and type two supernova,
Speaker 1: despite showing different elements in their spectra, all explode the
Speaker 1: same way. They start out so huge, possibly eight times
Speaker 1: the size of our Sun that they cannibalize themselves to
Speaker 1: the point of collapse. A white dwarf eventually created from
Speaker 1: a star that massive, has so much heat and pressure
Speaker 1: inside its core that lighter elements keep fusing into increasingly
Speaker 1: heavy elements instead of flying off into space. This produces
Speaker 1: enough radiating energy to support the star's increasing weight until
Speaker 1: iron forms. The fusion of iron into heavier elements actually
Speaker 1: uses energy rather than giving it off, so when iron
Speaker 1: begins to fuse, the star's outer layers lose their support
Speaker 1: and begin to fall inward. To understand the huge explosion
Speaker 1: that results, you have to know what's going on with
Speaker 1: the star's tiniest particles. When a white dwarf is massive
Speaker 1: enough to fuse the iron in its core, those iron
Speaker 1: atoms are incredibly hot and densely packed, squashed together like
Speaker 1: sweaty clowns stuck in a circus car. Their sub atomic
Speaker 1: particles collide and the iron atom's nuclei split, leaving behind
Speaker 1: helium nuclei plus a few leftover neutrons, and absorbing a
Speaker 1: lot of energy in the process. That energy was holding
Speaker 1: the star's core up, so without it, the core starts
Speaker 1: shrinking rapidly. It goes from a diameter of some five
Speaker 1: thousand miles to only twelve miles real Suddenly that's about
Speaker 1: eight thousand kilometers to just nineteen. This creates temperature somewhere
Speaker 1: in the region of one hundred and eighty billion degrees
Speaker 1: fahrenheit or one hundred billion degrees celsius, though at that
Speaker 1: point who's really counting. The heat causes protons and electrons
Speaker 1: to fuse together, canceling each other out to become neutrons
Speaker 1: and expelling a bunch of neutrinos in the process. The
Speaker 1: neutrinos can escape, so they do, leaving the core with
Speaker 1: even less energy to hold itself up. The core contracts
Speaker 1: as much as it physically can, but the star's outer
Speaker 1: layers keep falling inward even after there's no more room.
Speaker 1: That's when they rebound in that enormous explosion. All of
Speaker 1: that took a lot of words to explain, but it
Speaker 1: can happen in as little as a quarter of a second.
Speaker 1: The explosion is hot enough to fuse elements far heavier
Speaker 1: than iron, and it releases these elements in a gaseous
Speaker 1: cloud that will become an asymmetrical remnant around the remaining
Speaker 1: solid core. What happens next depends on how massive the
Speaker 1: original star was. If its inner core was less than
Speaker 1: three solar masses, it creates a neutron star with a
Speaker 1: core about as dense as an atom's nucleus and a
Speaker 1: powerful magnetic field. If its magnetic field creates lighthouse style
Speaker 1: beams of radiation that flash toward Earth as the star rotates,
Speaker 1: it's called a pulsar. But when a star with the
Speaker 1: core equal to three solar masses or more explodes, that
Speaker 1: can result in a black hole. A scientist's hypothesize that
Speaker 1: black holes form when gravity causes the stars compressed inner
Speaker 1: core to continually sink into itself. A black hole has
Speaker 1: such powerful gravitational force that it can drag surrounding matter,
Speaker 1: even planets, stars, and light itself into its mall, all
Speaker 1: of their powers of destruction. Aside, a lot of good
Speaker 1: can come of a supernova, and by tracking the demise
Speaker 1: of particular stars, scientists have uncovered ancient astronomical events and
Speaker 1: predicted future changes in the uns. And by using type
Speaker 1: one A supernova as standard candles, researchers have been able
Speaker 1: to map entire galaxies distances from us and determine that
Speaker 1: the universe is in fact expanding ever more rapidly. But
Speaker 1: of course, exploding stars leave more than just an electromagnetic
Speaker 1: signature behind. They also produce cosmic debris and dust. Type
Speaker 1: one a supernova are thought to be responsible for the
Speaker 1: large amount of iron in the universe, and all of
Speaker 1: the elements in the universe that are heavier than iron,
Speaker 1: from cobalt to rent genium, are thought to be created
Speaker 1: during core collapse supernova explosions. After millions of years, these
Speaker 1: remnants commingle with space gas to form new interstellar life
Speaker 1: baby stars that mature, age and may eventually complete the
Speaker 1: circle of life by becoming a supernova themselves. Today's episode
Speaker 1: is based on article how supernova works on HowStuffWorks dot com,
Speaker 1: written by Laureel Dove. Brain Stuff is production of iHeartRadio
Speaker 1: in partnership with how stuffworks dot Com and is produced
Speaker 1: by Tyler Klang. For more podcasts my heart Radio, visit
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