WEBVTT - How Powerful Are Magnetars?

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<v Speaker 1>Welcome to brain Stuff, a production of I Heart Radio, Hey,

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<v Speaker 1>brain Stuff learned Boba bam here. Our knowledge of the

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<v Speaker 1>universe is always expanding, much like the universe itself. This

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<v Speaker 1>means that we occasionally discover something new or come up

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<v Speaker 1>with a new model to explain data that we didn't

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<v Speaker 1>quite understand before. One such astronomical phenomena is the magnetar

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<v Speaker 1>type of powerful neutron star, the existence of which was

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<v Speaker 1>first proposed in that year astronomers suggested that certain blasts

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<v Speaker 1>of gamma and X ray radiation and radio pulses might

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<v Speaker 1>be explained by stars with exceptionally powerful magnetic fields. Since then,

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<v Speaker 1>astronomers have identified dozens of such magnetars in and around

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<v Speaker 1>the Milky Way. If you're curious about what a magnetar is,

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<v Speaker 1>how they come to exist in the galaxy, and why

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<v Speaker 1>astronomers consider them among the scariest objects in the universe,

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<v Speaker 1>this episode is for you. First, let's talk about how

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<v Speaker 1>magnetars are born. The stars go through a life cycle,

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<v Speaker 1>like everything else in the universe. What happens to a

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<v Speaker 1>star at the end of its life depends on the

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<v Speaker 1>mass of the star. For example, our sun is expected

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<v Speaker 1>to grow into a red giant, then become a planetary nebula,

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<v Speaker 1>then turn into a white dwarf star. More massive stars

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<v Speaker 1>can explode into supergiants, erupt into supernova, and then become

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<v Speaker 1>either a neutron star or a black hole. Magnetars are

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<v Speaker 1>the remnants of those massive stars which have exploded in

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<v Speaker 1>a supernova and collapsed into a neutron star. While astronomers

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<v Speaker 1>don't yet know what causes a supernova to result in

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<v Speaker 1>a magnetar instead of a normal neutron star or pulsar,

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<v Speaker 1>some hypothesize that it has to do with the original

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<v Speaker 1>stars rotational speed. In any case, magnetars are neutron stars

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<v Speaker 1>with magnetic fields of approximately tend to the power of

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<v Speaker 1>thirteen to tend to the power of fifteen gals, which

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<v Speaker 1>is a measure of magnetic density. This is a scale

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<v Speaker 1>of magnetic power that's hard to conceive, but let's just

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<v Speaker 1>say that magnetars are considered to be the most powerful

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<v Speaker 1>magnetic objects in the known universe. Scientists have confirmed the

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<v Speaker 1>presence of twenty three known magnetars, and another six are

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<v Speaker 1>waiting additional data to confirm if they meet the criteria

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<v Speaker 1>to be considered. Many of these are located in the

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<v Speaker 1>Milky Way, but don't worry, none are close to Earth.

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<v Speaker 1>The nearest is about nine thousand light years away in

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<v Speaker 1>the constellation Karina, another is some twenty thousand light years

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<v Speaker 1>away in Aquila, and yet another is about fifty thousand

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<v Speaker 1>light years away in Sagittarius. These distances are obviously far

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<v Speaker 1>beyond anywhere we've explored in our galaxy or even sent

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<v Speaker 1>probes like Voyager one or two to visit. While the

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<v Speaker 1>stellar life cycle that leads to a magnetar can take

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<v Speaker 1>millions or billions of years, magnetars themselves have a relatively

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<v Speaker 1>short cosmic life. The magnetic field of a magnetar begins

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<v Speaker 1>to decay after roughly ten thousand years. This means that

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<v Speaker 1>the magnetars that we see in our galaxy today are

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<v Speaker 1>just a few of the many magnetars that have ever existed.

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<v Speaker 1>The scientists estimate that there may be as many thirty

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<v Speaker 1>million inactive magnetars in the Milky Way alone. Okay, but

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<v Speaker 1>how do magnetars compare with the power of black holes?

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<v Speaker 1>Black holes are also certainly not the kind of thing

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<v Speaker 1>would want close to Earth before the article. This episode

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<v Speaker 1>is based on How's to works book by email with

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<v Speaker 1>Phil Plate, the astronomer who shares his insights, and the

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<v Speaker 1>Moniker Bad astronomer. He explained that it depends on what

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<v Speaker 1>force you're measuring. Quote, the gravity from the black hole

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<v Speaker 1>will always be stronger because the lowest mass black hole

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<v Speaker 1>is always more massive than the most massive neutron star,

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<v Speaker 1>but the magnetism of the magnetar will be stronger. In general,

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<v Speaker 1>Luckily will never have to worry about encountering a black

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<v Speaker 1>hole or magnetar close to Earth, but both could theoretically

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<v Speaker 1>impact us here on Earth even from far away. Plate said,

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<v Speaker 1>if a stellar mass black hole eats something, it could

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<v Speaker 1>blast out radiation, but even then I doubt it would

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<v Speaker 1>be as strongly felt from halfway across the galaxy as

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<v Speaker 1>the two thousand four make guitar event. That event was

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<v Speaker 1>a massive gamma and X ray blast from the aforementioned

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<v Speaker 1>magnetard that's fifty thousand light years away in Sagittarius. The

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<v Speaker 1>blast passed over Earth in two thousand four and caused

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<v Speaker 1>disruptions to satellite technology, among other issues. Okay, so magnatars

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<v Speaker 1>are indeed scary, but how present is the threat if

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<v Speaker 1>at all? A Plate said, I am worried about magnetars

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<v Speaker 1>given what happened in two thousand four, the one responsible

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<v Speaker 1>is exceptionally powerful. I don't think that any that strong

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<v Speaker 1>are closer to Earth, but the impact on Earth gets

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<v Speaker 1>stronger with the inverse of the distance squared. If one

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<v Speaker 1>were one fifth that distance, the impact would be twenty

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<v Speaker 1>five times stronger. Not only what a strong magnetar pulse

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<v Speaker 1>effect are electronics and other technology, but one with enough

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<v Speaker 1>length would affect our physiology, including the bioelectricity in our

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<v Speaker 1>bodies and between the atoms that make up everything we know.

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<v Speaker 1>Let's just say we should all be glad, but the

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<v Speaker 1>nearest known magnentar is nine thousand light years away. Today's

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<v Speaker 1>episode is based on the article why our mag guitar

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<v Speaker 1>is so scary on how stuff works dot Com, written

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<v Speaker 1>by Valerie steam App. Brain Stuff is a production of

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<v Speaker 1>I Heart Radio in partnership with how stuff Works dot Com,

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<v Speaker 1>and it's produced by Tyler Clang. Four more podcasts my

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<v Speaker 1>heart Radio, visit the heart Radio app, Apple Podcasts, or

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