# Two Supermassive Black Holes observed orbiting each another



## Brian G Turner (Jun 28, 2017)

https://phys.org/news/2017-06-groundbreaking-discovery-orbiting-supermassive-black.html


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## J Riff (Jun 28, 2017)

"... the galaxy named 0402+379...?"      Imagine using those things to slingshot your spaceship up to ludicrous speed.


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## Vertigo (Jun 29, 2017)

Wow! Orbital period of 24,000 years and they managed to measure the movement in just 12 years. That's extraordinary!


> "If you imagine a snail on the recently-discovered Earth-like planet orbiting Proxima Centauri - 4.243 light years away - moving at 1 cm a second, that's the angular motion we're resolving here,"


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## Alexa (Jul 1, 2017)

I'm glad they are far away. I wouln't like to fall in and wake up 1 000 years later in the future.


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## BAYLOR (Sep 24, 2017)

Alexa said:


> I'm glad they are far away. I wouln't like to fall in and wake up 1 000 years later in the future.



Black holes By far the most destructive force and creative force In all of nature,  without them, there would be no star formation, no light and no life.  
Eventually those two black holes will come together and become an even bigger Black holes. Perhaps thats the universe will end with black hole swallowing Black holes and all the matter in the universe and then, we get a new Big Bang and the whole thing stars al over again.


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## Alexa (Sep 24, 2017)

Not in our life time !


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## BAYLOR (Sep 25, 2017)

Alexa said:


> Not in our life time !



If a black hole were to suddenly appear near out system, we wouldn't detect it.


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## Vertigo (Sep 25, 2017)

BAYLOR said:


> If a black hole were to suddenly appear near out system, we wouldn't detect it.


I've often wondered about that...

If a black hole were relatively close to us but in an area of space where there are few background stars so that it's presence isn't revealed by its lensing effect (say well out of our galactic elliptical plane) and far enough away for its gravitational effect to be negligible then would it effectively be undetectable?


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## Venusian Broon (Sep 25, 2017)

Vertigo said:


> I've often wondered about that...
> 
> If a black hole were relatively close to us but in an area of space where there are few background stars so that it's presence isn't revealed by its lensing effect (say well out of our galactic elliptical plane) and far enough away for its gravitational effect to be negligible then would it effectively be undetectable?



How far away would a black hole need to be so that it's gravitational effect was 'negligible'? A naturally made Black hole would - unless there are such things like micro-blackholes - be at minimum about 3-4 times the mass of the Sun. I'd guess it could be pretty far out and still distort quite a lot of the planets orbits significantly - at least should be noticeable.

Not sure about what sort of distance is required for gravitational lensing, but I do believe the Sun should exhibit gravitational lensing (best placed at about 542 AU out apparently). That's pretty close in cosmic terms, so a black hole out at say 2 light years from Earth looks like it could be observed in this manner. I also think you won't be looking at nearby stars to lens but at very distant galaxies - of which they are everywhere.

I'd guess the best way to detect such an object, would be as an anomalous X-ray source, because any material falling into it would be ripped apart relativistically and generate these high energy photons.


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## Vertigo (Sep 25, 2017)

Venusian Broon said:


> How far away would a black hole need to be so that it's gravitational effect was 'negligible'? A naturally made Black hole would - unless there are such things like micro-blackholes - be at minimum about 3-4 times the mass of the Sun. I'd guess it could be pretty far out and still distort quite a lot of the planets orbits significantly - at least should be noticeable.
> 
> Not sure about what sort of distance is required for gravitational lensing, but I do believe the Sun should exhibit gravitational lensing (best placed at about 542 AU out apparently). That's pretty close in cosmic terms, so a black hole out at say 2 light years from Earth looks like it could be observed in this manner. I also think you won't be looking at nearby stars to lens but at very distant galaxies - of which they are everywhere.
> 
> I'd guess the best way to detect such an object, would be as an anomalous X-ray source, because any material falling into it would be ripped apart relativistically and generate these high energy photons.


Thanks @Venusian Broon; I was figuring on three or four light years away but yes I figured we'd still see the gravitational lensing on galaxies. But what I was thinking about was if we didn't know it was there and it was against a relatively "boring" background, would we even notice it? Also if it isn't actually "eating" anything, ie any "stuff" around it is in stable orbits. Given that, just how noticeable would it be? Always thought it would make a nice catastrophe story; suppose it's travelling towards the solar system at high speed and will pass within say one light year - close enough to disturb planetary and asteroid/Kuiper belt orbits - but we don't notice it until it's say two hundred years from having an effect. Giving us that long to prepare for maybe a new period of meteor bombardment...

As to it's origin; maybe it could have been thrown out of the galactic ecliptic plane by something like a close pass on another larger black hole (maybe even the one at the galactic centre) and we happen to cop it on it's return pass back through the ecliptic?


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## LordOfWizards (Sep 26, 2017)

"At roughly 750 million light years from Earth..." That's close in terms of the observable Universe. (13.8 Billion light years across). Not close enough to cause any concern of course. Also: "... says these supermassive black holes have a combined mass of 15 billion times that of our sun, or 15 billion solar masses."

Well, the folks in that galaxy were in for the ride of their lives, but since in spacetime that's also a "look-back time" of 750 million years, they've most likely already rode that one. It makes me wonder what that sort of thing would do to a galaxy like ours, and how long it would take to play out.

Astronomers have estimated the one at our galactic center to be 4.1 million solar masses. That's itty-bitty compared to the binary pair in the article.


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## BAYLOR (Sep 26, 2017)

LordOfWizards said:


> "At roughly 750 million light years from Earth..." That's close in terms of the observable Universe. (13.8 Billion light years across). Not close enough to cause any concern of course. Also: "... says these supermassive black holes have a combined mass of 15 billion times that of our sun, or 15 billion solar masses."
> 
> Well, the folks in that galaxy were in for the ride of their lives, but since in spacetime that's also a "look-back time" of 750 million years, they've most likely already rode that one. It makes me wonder what that sort of thing would do to a galaxy like ours, and how long it would take to play out.
> 
> Astronomers have estimated the one at our galactic center to be 4.1 million solar masses. That's itty-bitty compared to the binary pair in the article.



We seem to be dancing on the edge of a gravitational maelstrom abyss.


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## Venusian Broon (Sep 26, 2017)

BAYLOR said:


> We seem to be dancing on the edge of a gravitational maelstrom abyss.



Not really. The total mass of the milky way is estimated to be in the range 5.8-8.0 x 10 ^11 Solar masses or about 150,000 times larger than the mass of the black hole in the middle. Very roughly then the Earth experiences the mass of the centre as about just over a half of that (the mass that impacts us as part of the force that ties us to our galactic orbit)


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## hej (Oct 5, 2017)

Impressive.

On a similar subject, two years ago scientists discovered the first evidence of gravitational waves from the collapse of binary black holes.

First observation of gravitational waves - Wikipedia

They were moving significantly faster than the pair in the article you share.

"Across the 0.2-second duration of the detectable signal, the relative tangential (orbiting) velocity of the black holes increased from 30% to 60% of the speed of light."


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