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[Music] Narrator: A pulsar is the

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crushed core of an exploded star. Theorists have been

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trying to understand the details of how pulsars work ever since they were discovered

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in 1967 -- especially how they emit precisely

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timed pulses at radio to gamma-ray energies.

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Now, new computer simulations are providing surprising insights.

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A pulsar contains some of the strongest magnetic fields known

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and can spin thousands of times a second. That means it's a

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powerful dynamo, generating an electric field so strong

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particles are ripped out of the surface and accelerated into space.

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New computer simulations clearly show these incredible movements for the

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first time. Most of these particles are electrons and their

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antimatter counterparts, positrons. In these simulations,

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their colors get lighter as they attain higher energies.

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Electrons tend to race outward from the magnetic poles.

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Positrons mostly flow out at lower latitudes along a relatively thin structure

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called the current sheet. Ultimately, these

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outflows lead to the formation of a powerful wind that extends far from

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the pulsar. Magnetic field lines

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and the particles moving with them, sweep back and extend outward as the

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pulsar spins. Their rotational speed rises with greater distance,

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but there's a wall created by the ultimate speed limit -- 

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the speed of light. Astronomers call this the light cylinder.

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Matter can't travel at the speed of light, so something has to give

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before the particles get this far. Just before reaching

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the light cylinder, these simulations show that a population of medium-energy

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electrons scatter wildly -- sometimes even back toward the pulsar.

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Some speed up, others slow. Most

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eventually slip past the light cylinder and head out into space.

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The simulations also show that a small percentage of positrons

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likely hold the secret to a pulsar's gamma-ray emission.

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Some of these particles become boosted to tremendous energies at points within

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the current sheet where magnetic field lines meet. These simulations

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bring scientists one step closer to understanding the incredible physics

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of pulsars, something that has kept theorists busy for decades.

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[Music]

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[These visualizations use data from simulations by Brambilla et al., 2018]

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[Beeping]

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[Beeping]