Monday, 16 October 2017

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A Groundbreaking Astronomy Discovery! Spot Spectacular Two neutron stars collided in space

It was a faint signal, but it told of one of the most violent acts in the universe, and it would soon reveal secrets of the cosmos, including how gold was created.

Astrophysicists today have released no less than seven papers on one of the biggest events not only reported in the media but also in the known universe. For the first time ever, we have definitive evidence of two neutron stars colliding and releasing a deadly gamma-ray burst. The light from this burst arrived almost simultaneously with gravitational waves unleashed by the collision.
For the first time, scientists have caught two neutron stars in the act of colliding, revealing that these strange smash-ups are the source of heavy elements such as gold and platinum.

The discovery, announced today at a news conference and in scientific reports written by some 3,500 researchers, solves a long-standing mystery about the origin of these heavy elements — which are found in everything from wedding rings to cellphones to nuclear weapons.

It's also a dramatic demonstration of how astrophysics is being transformed by humanity's newfound ability to detect gravitational waves, ripples in the fabric of space-time that are created when massive objects spin around each other and finally collide.

"It's so beautiful. It's so beautiful it makes me want to cry. It's the fulfillment of dozens, hundreds, thousands of people's efforts, but it's also the fulfillment of an idea suddenly becoming real," says Peter Saulson of Syracuse University, who has spent more than three decades working on the detection of gravitational waves.
Albert Einstein predicted the existence of these ripples more than a century ago, but scientists didn't manage to detect them until 2015. Until now, they'd made only four such detections, and each time the distortions in space-time were caused by the collision of two black holes.

That bizarre phenomenon, however, can't normally be seen by telescopes that look for light. Neutron stars, by contrast, spew out visible cosmic fireworks when they come together. These incredibly dense stars are as small as cities like New York and yet have more mass than our sun.
In this case, what scientists managed to spot was a pair of neutron stars that likely spent more than 11 billion years circling each other more and more closely before finally slamming together about 130 million years ago.

What was different this time?

The first four observed gravitational waves were all caused by two black holes rapidly orbiting each other and eventually colliding, forming a new and larger black hole. However, black hole mergers are not the only events that can produce gravitational waves.

Black holes are part of a group called compact objects: they are the remains of a star after it has died. The two other main compact objects are white dwarfs and neutron stars. The former is formed when a star up to eight times the mass of our Sun expands as it grows old and sheds its outer layers, retaining only the core. A neutron star is formed when a star that weighs more than eight- to thirty-times the solar mass explodes in a supernova. (By the way, supernovae also produce gravitational waves).

Neutron stars are the smallest and densest stars in the universe (even though they don’t make their own energy). Such an object will weigh 1.5-2 times the Sun but will measure only 10-20 km wide. A teaspoon of neutron star material would be heavier than Mt Everest; a can of Coke will weigh more than all the humans on Earth combined. The particles in this structure are so tightly packed together that protons and electrons merge to form neutrons. So these objects are almost entirely made up of neutrons. They also spin rapidly, creating extremely powerful magnetic fields around themselves.