A massive star completely destroyed by a supernova is a puzzle for scientists



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Super Supernova

SN2016iet released a huge amount of energy when it exploded and took a long time to fade. This and other details led astronomers to think that it was a rare example of a pair-instability supernova. Usually, when massive stars explode, they leave behind something – a dense nucleus called a neutron star or a black hole.

But sometimes, theories of scientists predict that massive, low-metallicity stars (those with few elements other than hydrogen and helium) can begin to make pairs of matter and antimatter in their final days. This causes a runaway effect when the pressure drops in the star's core, causing a collapse and a huge explosion that completely destroys the star, leaving nothing behind, not even a black hole.

A star must be 130-260 times the mass of the Sun to die in this way. And such a massive star will quickly burn its fuel and live only a few million years.

Its huge size is part of what makes the SN2016iet location so confusing. Usually, massive stars are born in dense groups, not far from themselves. And since SN2016iet's star would have lived such a short life, she should have had nearby stars that survived her. It is possible that the star was driven from his home, but again, his short life limit the path traveled. To really get away from his apparent galaxy, it would have been necessary to send it at a speed exceeding by far all that scientists have measured.

The most plausible explanation is that the star is formed where astronomers see it, and is actually part of a satellite galaxy or cluster that is simply too dark to be seen.

The quirks remain

A star directed at such a cataclysm should also lose weight during the thousands of years that preceded his death, rejecting materials because of the dense solar winds. But the long-term observations of the star have produced a double peak of brightness that, according to Gomez, comes from the light produced by the supernova that produces shocks when it hits different layers of material. And this material is still quite thick and close to the star, which implies that it will lose all this mass in less than 20 years, instead of thousands. Gomez says that's another part of the puzzle.

SN2016iet is one of the best examples of torque unstable supernova in real life. It also questions many of the details about the actual appearance of these stars as they explode. Gomez and his team have already been approved for a place in the Hubble Space Telescope. They will use their time to make more follow-up observations and will also look for the galaxy or group of satellites that they believe would have housed the star-progenitor of the supernova. Gomez says the observations should be made in the next six months, hoping to answer more questions about this strange star.

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