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  • Gravitational waves resulting from crashing neutron stars have rocked our universe once again.

  • And while you may not have felt it, LIGO sure did.

  • And these gravitational waves are the ripples from a collision of the most massive neutron

  • star pair we have ever witnessed.

  • As you may know, this isn't LIGO's first rodeo with gravitational waves.

  • They're famous for the first ever detection of gravitational waves back in 2015, which

  • were the result of a black hole merger.

  • Then LIGO detected their first ever gravitational waves from a neutron star merger in 2017.

  • And this latest neutron star collision, observed in 2019, was given the catchy name...GW190425.

  • Just as a quick refresher, LIGO is the Laser Interferometer Gravitational-Wave Observatory.

  • It detects these tiny disturbances in the fabric of space-time, like ripples on the

  • surface of a pond.

  • They travel through the universe at the speed of light, and typically only distort physical

  • space here on Earth by about the width of an atom's nucleus.

  • And even though gravitational waves are practically infinitesimal by the time they reach us here

  • on Earth, the strongest ones we can measure with our instruments are caused by gigantic

  • cosmic events: like collisions of black holes or neutron stars.

  • The 2019 event was actually detected on only one of the two U.S. LIGO sitesthe one in Louisiana

  • because the detector in Washington was offline.

  • This is LIGO's first single-detector event, which is impressive, but it also means researchers

  • weren't able to narrow down the merger's location as much as they might have been able

  • to with two detectors online.

  • Though as of right now, the merged neutron stars could exist anywhere in an area that makes

  • up about 20% of the sky, not exactly a small window.

  • The team deduced from the data that the combined mass of the two neutron stars was about 3.4

  • times greater than the mass of our Sun, making it the most massive neutron star merger we've

  • ever observed.

  • And it's different from the 2017 event, too, because it wasn't accompanied by any

  • kind of electromagnetic radiation that we could detectit was missing what some scientists

  • call a 'flash of light'.

  • And perhaps most intriguingly, it appears to have created an object withunusually

  • high mass”.

  • Higher mass than we've ever seen before from a neutron star merger, and higher than

  • we expected.

  • With this second observation of neutron stars colliding, scientists are gathering clues

  • about how these cosmic events affect our universe.

  • A neutron star is a super-dense remnant of a star after it erupts into a supernova.

  • They're basically laboratories of really extreme physics.

  • They tell us a lot about space and how it evolves over time, so to witness and measure

  • a collision of two of them can yield some really rich insights.

  • Like LIGO's observation of this in 2017 was the first ever, yes, so very exciting

  • But it also yielded data confirming the hypothesis that neutron stars crashing into each other

  • are a source of heavy elements, producing stuff like gold and platinum.

  • They're basically heavy element factories.

  • And we still don't know a lot about what happens to neutron stars after they merge

  • togetherso scientists were hoping this latest detection would drop some hints.

  • All of the data from this 2019 eventthe massive object left behind in the merger's

  • wake, plus the lack of electromagnetic radiationleads some scientists to believe that these two

  • neutron stars may have become a black hole after they merged.

  • Maybe.

  • But it could also just be that we weren't looking in the right place at the right time

  • and we missed the flash of light.

  • So astrophysicists are going to keep probing this data to see if they can gain any more

  • insights, and hopefully LIGO will capture many more events like this in the future to

  • tell us even more about the crazy cosmic collisions that both create and disturb the very fabric

  • of our universe.

  • In order to do this, LIGO does has some serious upgrades planned, so check out this video here

  • to learn all about that.

  • And make sure you subscribe to Seeker for all things space-time.

  • If you have another cosmic event you want to see us cover, let us know down in the comments

  • below and as always, thanks so much for watching.

  • I'll see you next time.

Gravitational waves resulting from crashing neutron stars have rocked our universe once again.

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This Is the Biggest Neutron Star Collision We’ve Ever Detected

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    林宜悉 posted on 2020/04/04
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