J0806

tullio
tullio
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Topic 192565

This is from NASA:

"About 1,600 light-years away, in a binary star system fondly known as J0806, two dense white dwarf stars orbit each other once every 321 seconds. Based on data from the Chandra X-Ray Observatory, astronomers believe that the stars' already impressively short orbital period is steadily becoming shorter. Because of this, the two stars are destined to merge.
Depicted in this artist's vision, the death spiral of the remarkable J0806 system is a consequence of Einstein's theory of General Relativity that predicts the white dwarf stars will lose their orbital energy by generating gravity waves. In fact, J0806 could be one of the brightest sources of gravitational waves in our galaxy, directly detectable by future space-based gravity wave "instruments."

Could LIGO see it?
Tullio

Mike Hewson
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J0806

Quote:

This is from NASA:

"About 1,600 light-years away, in a binary star system fondly known as J0806, two dense white dwarf stars orbit each other once every 321 seconds. Based on data from the Chandra X-Ray Observatory, astronomers believe that the stars' already impressively short orbital period is steadily becoming shorter. Because of this, the two stars are destined to merge.
Depicted in this artist's vision, the death spiral of the remarkable J0806 system is a consequence of Einstein's theory of General Relativity that predicts the white dwarf stars will lose their orbital energy by generating gravity waves. In fact, J0806 could be one of the brightest sources of gravitational waves in our galaxy, directly detectable by future space-based gravity wave "instruments."

Could LIGO see it?
Tullio


At 1600 light years it's certainly close enough, but currently the frequency is too low @ ~ 0.003Hz. The 'sweet spot' for the LIGO's is centered around 200Hz. Later on when the system spirals in some more, it will enter the LIGO sensitivity range and produce a 'chirp' before the dwarfs merge. That might be quite a while yet though! Did they predict when the merger is likely? :-)

Future space based detector systems ( .. LISA ) are going to be much larger in size and thus deal with longer wavelengths and hence lower frequencies of signal response.

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

tullio
tullio
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RE: Did they predict when

Message 61795 in response to message 61794

Quote:

Did they predict when the merger is likely? :-)

Future space based detector systems ( .. LISA ) are going to be much larger in size and thus deal with longer wavelengths and hence lower frequencies of signal response.

Cheers, Mike.


No AFAIK. Cheers.
Tullio

adrianxw
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RE: Each year the orbit

Quote:
Each year the orbit period decreases for 1.2 milliseconds and the distance gets half a meter less. So the stars will crash together in several hundred thousand years.

From here.

Wave upon wave of demented avengers march cheerfully out of obscurity into the dream.

tullio
tullio
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RE: RE: Each year the

Message 61797 in response to message 61796

Quote:
Quote:
Each year the orbit period decreases for 1.2 milliseconds and the distance gets half a meter less. So the stars will crash together in several hundred thousand years.

From here.


So we won't see it. Will anybody?
Tullio

Ben Owen
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RE: At 1600 light years

Message 61798 in response to message 61794

Quote:


At 1600 light years it's certainly close enough, but currently the frequency is too low @ ~ 0.003Hz. The 'sweet spot' for the LIGO's is centered around 200Hz. Later on when the system spirals in some more, it will enter the LIGO sensitivity range and produce a 'chirp' before the dwarfs merge. That might be quite a while yet though! Did they predict when the merger is likely? :-)

Future space based detector systems ( .. LISA ) are going to be much larger in size and thus deal with longer wavelengths and hence lower frequencies of signal response.

Cheers, Mike.

Mike, it's true that this is a LISA source rather than a LIGO source. But even when these things are ready to merge they are not in the LIGO band. They are way too big (thousands of km) and thus touch early. This is contrast to neutron stars, which are about 10km across and thus can get deep into each other's gravitational fields and orbit at LIGO-band frequencies before merging.

Ben

Mike Hewson
Mike Hewson
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RE: ......... are way too

Message 61799 in response to message 61798

Quote:
......... are way too big (thousands of km) and thus touch early ....


Ah, of course, their size! :-)

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

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