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[MUSIC]

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[Inside the Image / Hubble Space Telescope]

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[V838 Mon]

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This is an object called V838

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Monocerotis, or V838 Mon,

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and it's a series

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of images of the same object

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that are taken over

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about a half a year or so in 2002.

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So, we see the central object

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here is the same

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in each of the four images.

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But what is immediately apparent is that

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there's an expanding

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brightness around it.

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So what was first thought would be that,

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wow, we've got this gas cloud

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that is just spewing away

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from this object,

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but it was spewing away

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at incredibly fast speeds.

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What is actually happening here,

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instead of that gas

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itself being in motion

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and causing that expansion

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is something called a light echo.

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So just like you hear an echo

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with sound waves, as some sound waves

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come directly towards you,

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you hear the main source of sound.

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But then as others bounce off walls

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and come to you a little bit later,

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that's where the echo comes from.

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The same thing is happening

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with light in this image.

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We're seeing some of that light

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coming directly towards us.

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We're seeing that

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at the time that we receive it.

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But some of the rest of the light

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is actually bouncing off material around

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that binary in the center.

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It bounces off it,

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and then it comes to us.

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That's the light echo.

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And so each one of those

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succeeding images

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where we see this shell

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further and further from the center

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is actually that light echo

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coming to us later in time.

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So we're actually basically

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taking a CAT scan

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of the material around that central star.

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There's still a lot of mystery

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surrounding

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where that material came from.

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Is it being blown off

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by these hot, young,

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energetic stars

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as a process of their star formation?

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One of the coolest possibilities

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is that one of these stars

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actually engulfed

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a giant planet in its orbit.

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So like a giant planet, like many times

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the mass of Jupiter could be in orbit

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very close to this very hot, large star.

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And the tidal forces

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and the energy dissipation

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could have been acting on it

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in such a way that that now

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massive planet

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is losing energy,

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spinning more rapidly

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and closer

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to one of those stars,

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and eventually gets engulfed in

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an explosive event.

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Could have been a large planet.

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Could have been

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a small star in that system.

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We don't know what the mass of that

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intruder

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was, that interloper

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that caused this explosive event.

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But it is very likely

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that it was something

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in the neighborhood

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of that binary system

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that just got too close

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to one of those stars, got sucked in,

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and we saw this explosion as a result.

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[MUSIC]

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