"What is dead may never die."
A supernova is a momentary astronomical event, which takes place during the last stellar evolutionary stages of a massive star's life, whose dramatic and catastrophic destruction is marked by one ultimate gigantic explosion. Every star reaches this point in its life when it explodes and shines the brightest right at the end of its time and then fades away into the deep dark space. However, scientists have recently found a massive, distant star in space, which had exploded back in 2014 and also, apparently, way back in 1954, but it just refuses to fade away.
This dying Supernova, which keeps coming back after every few years and becomes brighter than before every time when it is spotted, has left the scientists across the world perplexed, who thought they knew how dying stars ticked.
The star in question is located around 500 million light-years away from the Earth in the direction of the Big Bear constellation. It was discovered in 2014 and, at the time, resembled a basic supernova, which appeared to be getting fainter.
However, to everyone's surprise, a few months later, astronomers at the California-based Las Cumbres Observatory, noticed that the star was brighter again. They've observed the supernova to actually grow faint, then bright, then faint again five times. Following this, the scientists also dug out past evidence of an explosion at the same spot 60 years ago.
Supernovas typically fade over 100 days, at least, that's what scientists had known till now. This one is still going strong after 1,000 days, although it is gradually fading. But, you never know, it may come back brighter again.
The finding was published Wednesday in the journal Nature.
"It's very surprising and very exciting. We thought we've seen everything there is to see in supernovae after seeing so many of them, but you always get surprised by the universe. This one just really blew away everything we thought we understood about them," said astrophysicist Iair Arcavi of the University of California, Santa Barbara who led the study.
Scientists believe that the supernova, officially designated as iPTF14hls, had once been a star, which was up to 100 times more massive than our sun. It could very well be the biggest stellar explosion that has ever been observed, which might explain its death-defying peculiarity.
Also, it could be multiple explosions occurring so frequently that they run into one another or, perhaps, it is only one single explosion, which repeatedly gets brighter and fainter, although scientists do not have any idea as of yet, as to how exactly that's possible.
According to Arcavi, one possibility is that this star was once so enormous, and its core so hot, that one explosion blew away the outer layers and left the centre intact enough to repeat the entire process over and over again. However, this vivacious theory still doesn't explain everything about this supernova.
A neutron star with a strong magnetic field can also at the centre of this never-seen-before- behaviour, opines Harvard University's astronomy chairman, Avi Loeb, who was not involved in the study.
Las Cumbres, a global network of robotic telescopes, is still observing the star and its proceedings.
"We could actually have missed plenty of them because it kind of masquerades as a normal supernova if you only look at it once," Arcavi said. "Eventually, this star will go out at some point. I mean, energy has to run out eventually."
Well, let's wait and watch what becomes of this beautiful yet bizarre supernova in the future.