Einstein@Home discovers a record-breaking pulsar-neutron star system

AgentB
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Topic 203629

I didn't see it in the the news!  Wow.

Mike Hewson
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I missed that too ! You could

I missed that too ! You could put this one in your realty folder though : this binary system will last about another 500 million years and I would flog it as a good long term investment. !! :-))

- another rare bird from E@H, the most massive double neutron star system found to date .... yeah ! :-)

- the signal was picked up with high dispersion modulus applied ie. from quite a cosmic distance c/w other pulsars.

- we've detected the larger one of the pair which is radiating to us. Each has a Sun's worth or so of mass, but if sufficiently asymmetrically so : this implies that one maybe ripping the other up through large tides.

- they are separated by a little more than the Earth-Moon distance with nearly twice the eccentricity ie. how much not-quite-a-circle.

- the acceleration of one NS felt by the other is around 6 times here on Earth's surface, giving a five hour orbit. Whereas the Moon, in one second, will 'fall' a fraction of an inch ( away from the line it would have traveled if the Earth wasn't there ) this will fall 27 metres.

- so imagine an entire star of some 20km diameter pulling gees like a jet fighter, but out there near the Moon. This is intense gravity ......

- the emitting pulsar has probably been around for 2.5 billion years.

- they've probably been together for about 100 million years.

- will they form a black hole when they merge ????

Cheers, Mike.

( edit ) BOTE orbital velocity is ~ 190 km/sec. Compare that with Earth's surface escape velocity which is 7.9 km/s ie. in this DNS you have to be packing 24 times that just to stay in orbit.

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

AgentB
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Mike Hewson wrote:I missed

Mike Hewson wrote:
I missed that too ! You could put this one in your realty folder though : this binary system will last about another 500 million years and I would flog it as a good long term investment. !! :-))

Yes Big G Realty would have a few premier spots.  Top of the list would be the the small oasis [1] at the centre of gravity about which these two NS do their dance. 

If you could see their surfaces (assuming they emit some visible light) they would be about the size of Venus, but i expect you notice the stars behind them being moved about quite a bit, and colours of stars i guess would change as well.

For amusement you could throw rocks, and when they each impacted probably just a few hours later the kinetic energy energy released would be of the order on 10 kilotons of TNT!

Getting to and escaping from this place would need an interesting and rather careful approach.

[1] Restaurant at the end of the universe.

Mike Hewson
Mike Hewson
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The C of G would still be a

The C of G would still be a rowdy spot, an unstable equilibrium. Eye of the hurricane type of thing, or centre of a twister vortex. You could come in out of the plane of mutual orbit ie. along the perpendicular. I think the fun in throwing the rocks could be in accurately predicting where it would hit, and this would require some finesse and/or calculation. For sure it'll dive into one or the other's gravity well but you'd have to anticipate alot. Like me playing darts : I might hit the board. These stars are small targets with tiny angular width and moving across your field of view at greater than one degree per minute !

NB The system is gauged at 1.75 light seconds for the semi-major axis ( ~ half the width if you like ) ie. 1.75 times 300,000 kilometres = 525,000 km. The Moon is about 380,000 km away. In stellar terms that's a close cuddle.

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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