The SN2016iet was releasing a huge amount of energy when it exploded and took a long time to fade. This and other details made astronomers think it was a rare example of superficial instability. Usually, when massive stars explode, they leave something behind – either a dense nucleus called a neutron star or a black hole.
But sometimes theories of scientists predict that massive stars and low-metal metals (those with few elements other than hydrogen and helium) can start to make pairs of matter and antimatter in their last days. This causes an escape effect whereby the pressure falls into the core of the star, causing it to collapse, leading to a huge explosion that completely destroys the star, leaving nothing behind, even a black hole.
One star must be 130-260 times the mass of the sun to die in this way. And such a massive star will burn through its fuel quickly, living only a few million years.
Its huge size is part of what makes the SN2016iet's isolated location so puzzling. Usually, massive stars are born in dense clusters, not far away by themselves. And since the SN2016iet star would have such a short life, it must have close stars that outlive it. The star may be banished from her original home, but again her short life span limits how far she can go. To get this far from its seeming receiving galaxy, it will have to be thrown out at a speed far beyond anything scientists have yet measured.
The most plausible explanation is that the star formed exactly where astronomers see it, and that it is actually part of a satellite galaxy or cluster that is just too dark to see.
The weirdness remains
A star targeting such a cataclysm is also expected to throw mass thousands of years before his death, throwing material through dense solar winds. But long-term observations of the star have led to a double peak of brightness, which Gomez says is from the light of the supernova, which causes shocks as it hits different layers of material. And this material is still quite thick and close to the star, suggesting that instead it casts this whole mass in less than 20 years instead of thousands. Gomez says this is another part of the puzzle.
The SN2016iet is one of the best examples of supernatural instability in real life, and it also challenges many of the details of how these stars actually look when they explode. Gomez and his team have already been approved for the Hubble Space Telescope slot. They will use their time to make more follow-up observations and also to search for a satellite galaxy or cluster suspected to have housed the supernova's offspring. Gomez says the observations must be made within the next six months, hopefully answering more questions about this strange star.