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"Inside the Image, Hubble Space Telescope."

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"N44 Superbubble"

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N44 is what's called an emission nebula it has 
this bright glowing gases that you see here it's  

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in what's called the Large Magellanic Cloud.
This image is about a thousand light years  

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across so it's a fairly large nebula this 
dark void in the center is about 250 light  

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years across and that is something called a 
Superbubble area in the nebula that's been  

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completely cleared out all around it we have 
dust and gas at various temperatures, various  

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densities, inside of that bubble we only have 
what's called ionized gas it's very hot gas.  

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One of the puzzles in this image or 
competing ideas and they're probably both  

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contributing here, neither one seems to be the 
ultimate solution, one is that the winds of stars  

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inside the void which include high energy, high 
speed particles coming out from the surface of  

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the stars pushing material clearing it out of the 
center. The other possibility or the other thing  

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that's probably contributing to the clearing of 
this Superbubble is supernova. Supernova at the  

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end of their life if they're massive stars explode 
which sends out both particles and radiation; these  

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particle waves that are coming out can act as a 
snow plow and basically clear out the the void and  

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push it up against this outer ridge that we see 
here. If these are happening you should see around  

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this border stars in the process of formation and 
in fact we do see stars there and there were about  

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five million years different in age than the stars 
that are inside they have formed later after this  

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compression has happened from the clearing of the 
inside. It is still expanding not not super fast  

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it appears that the near edge is coming toward 
us at about 45 kilometers per second the far  

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edge is receding at maybe 30, so it's asymmetric 
which is interesting it's moving a little faster  

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on one side than the other. It's called the Superbubble because of its size if we go to smaller and  

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smaller bubbles they become more and more frequent 
to see a volume of space this large that has been  

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cleared out so completely is very rare and it's 
it's super in that way also super just in size!

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