Undying supernova: a star is emerging from five explosions

Discovered star zombie has puzzled scientists.

Astronomers have found a star zombie, five times survived the transformation into a supernova. This star – space equivalent of a character from a horror movie about zombies, because she did not want to die completely.

According to scientists, normally, when stars become supernova, they die as a result of a single explosion. However, astronomers have found a star, a survivor of not one, but five such explosions.

According to the observations of an international group of scientists, this star-zombies continued to explode for nearly two years – six times longer than is normally occurs at the appearance of a supernova. “This supernova turns everything we know about these stars. It’s the biggest mystery I’ve encountered in nearly a decade of observations of the explosions of stars,” says co-author scientific articles Yair Arcavi, an employee of the California division of the Las Cumbres Observatory.

A mysterious celestial body called iPTF14hls started to follow in September 2014 during exploration of outer space using the wide field camera. In January 2015, astronomers have classified this object as an exploding star, and at first nothing unusual in her behavior was not observed. With the appearance of an ordinary supernova explosion in the center of the star with great speed throwing a large mass of matter from its outer shell into the surrounding interstellar space.

The expansion of matter releases a huge energy, causing a bright glow, lasting up to 100 days, after which the star fades. But in the case of iPTF14hls it soon became clear that this star is not going to behave according to the expectations of scientists. First, it was not extinguished, but continued to glow brightly 600 days. Second, astronomers found that the brightness of the stars varies in the range of up to 50% without any regularity – as if it explodes again and again. And instead of cooling off as expected, the object continued to maintain almost a constant temperature of about 5700 degrees Celsius. More and more scientists intrigued by the fact that, combing the archives, they discovered the explosion, recorded in the same place in 1954. This finding suggests that tens of years ago, the star survived the explosion, again to detonate after 60 years in 2014.

Star iPTF14hls may be the first known example of so-called pulsating pair-instability supernova. It is believed that pair-unstable supernovae occurred in the early stages of the Universe in the explosions of the first stars, entirely composed of hydrogen and helium. They were much heavier than even the big modern stars. “The theory is that, possibly as a result of the explosion of a star so massive and hot that at its core had the antimatter,” says a scientist at the University of California, Berkeley Daniel Kasen.

“This was supposed to lead to highly unstable behavior of the stars and a series of bright explosions for several years,” he says. This process can be repeated over dozens of years, before followed by a final explosion and the transformation of a star into a black hole.

But scientists still do not understand a lot.

“At the moment not published a detailed model that can explain the observed emission and a constant temperature iPTF14hls, not to mention a possible explosion 60 years ago,” says University of California Walls Woolsey. “So far, the supernova offers astronomers the most exciting for them: something that they can’t understand,” the scientist said.

Earlier, the astronomers of the Earth called the oldest spiral galaxy in the Universe.

Also astronomers have found the nearest to the Earth the double black hole.

paradox