(USA TODAY) -- It's the star that refused to die.
Astronomers have discovered a star that exploded multiple times over a period of more than 50 years, a new study says.
Known as a supernova, it could also have been the most massive and the longest-lived exploding star ever seen.
"This supernova looked like nothing we had ever seen before," said Peter Nugent, a scientist at Lawrence Berkeley National Laboratory who co-authored the study. "This, after discovering nearly 5,000 supernovae in the last two decades.”
When the supernova, which has the inelegant name of iPTF14hls, was discovered in September 2014, it looked like a typical supernova. But several months later, scientists noticed that the supernova, once faded, was growing brighter. It was a phenomenon they had never seen before.
Additionally, when astronomers went back and looked at archival data, they were astonished to find evidence of an explosion in 1954 at the same location. This star somehow survived that explosion and exploded again in 2014.
Astronomers have observed thousands of supernovas over the decades, and in all cases they marked the death of a star.
“This supernova breaks everything we thought we knew about how they work. It’s the biggest puzzle I’ve encountered in almost a decade of studying stellar explosions,” said study lead author Iair Arcavi, a postdoctoral fellow at the Las Cumbres Observatory and the University of California Santa Barbara (UCSB).
The fact that it exploded more than once was amazing, but the size and duration of the explosion were also noteworthy.
"Supernova iPTF14hls may be the most massive stellar explosion ever seen," explained co-author Lars Bildsten, also of UCSB. "For me, the most remarkable aspect of this supernova was its long duration, something we have never seen before."
Scientists say a definitive explanation for what they saw remains elusive, and the authors suggest that current models of massive star evolution and explosion need to be revised to account for this unusual event.
The study was published Wednesday in the peer-reviewed British journal Nature.