# Witnessing a black hole's destruction of a star



## j d worthington (Dec 6, 2006)

Scientists have been tracking the slow destruction of a star that has wandered too near a galactic black hole in Bootes:

NASA telescope sees black hole gulping remote star - Yahoo! News

Would be a fascinating and awe-inspiring thing to watch.......


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## Paige Turner (Dec 6, 2006)

astonomer guy said:
			
		

> It is believed that super-massive black holes are located at the core of every galaxy. For example, Gezari said, the Milky Way galaxy in which our solar system resides has a dormant super-massive black hole at its center.



What's a _dormant_ black hole?


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## j d worthington (Dec 6, 2006)

Paige Turner said:


> What's a _dormant_ black hole?


 
Can Black Holes become dormant?

Constellation-X :: Public :: Science Goals

The relevant passage from the second link is this:



> Our own galaxy probably contains a dormant supermassive black hole at its center. Weak X-ray emission emanates from near the galactic center. This appears to be a fossil "footprint" of a once-active black hole.


 
Chandra Press Room :: Chandra Uncovers New Evidence For Event Horizons Surrounding Black Holes :: January 11, 2001



> By comparing the energy output from the dormant X-ray novas, the team discovered that the sources with black holes emitted only one percent as much energy while dormant as did the X-ray novae with neutron stars.



Spaceflight Now | Breaking News | Growing black holes control galaxy formation



> Di Matteo and her colleagues simulated the collision of two nascent galaxies and found that when the two galaxies came together, their two supermassive black holes merged and initially consumed the surrounding gas. But this activity was self-limiting. As the remnant galaxy's supermassive black hole sucked up gas, it powered a luminescent state called a quasar. The quasar energized the surrounding gas to such a level that it was blown away from the vicinity of the supermassive black hole to the outside of the galaxy. Without nearby gas, the galaxy's supermassive black hole could not "eat" to sustain itself and became dormant. At the same time, gas was no longer available to form any more stars.


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## Riker (Dec 16, 2006)

I'm not totally up on science but if there is a black hole in the middle of our galaxy and its dormant, if it became active it would swallow our sun right?  According to that article it took about a yearish for that black hole to swallow the planet, would the sun take just as long?


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## j d worthington (Dec 16, 2006)

Riker said:


> I'm not totally up on science but if there is a black hole in the middle of our galaxy and its dormant, if it became active it would swallow our sun right? According to that article it took about a yearish for that black hole to swallow the planet, would the sun take just as long?


 
No, it wouldn't swallow our sun, as we're very far out from the center of the galaxy. The only illustration I found is from a rather simplistic site, but it helps to visualize it:

The Milky Way Galaxy - Zoom Astronomy

For more information:

Milky Way - Wikipedia, the free encyclopedia

As for how long it would take a black hole to swallow our sun ... I've no idea of the figures, but from what I've seen on the subject, it's a _very_ long process. *Very* long.


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