High in the night sky, within the Great Bear constellation, a stellar mystery is unfolding half a billion light-years away.
Astronomers are bewildered by a star that defies the usual expectations of supernovae, refusing to conform to the single explosive finale that marks the end of a star’s life.
This star, known as a ‘zombie’ for its repeated resurrections, has astonished experts with a display that seems straight out of science fiction.
The perplexing object, named iPTF14hls, first caught attention in September 2014. Yet, it wasn’t until January the following year that it was identified as an exploding star.
What sets iPTF14hls apart from its cosmic counterparts is its defiance of the one-and-done nature of typical supernovae. “This is the weirdest supernova we’ve ever seen,” exclaimed Iair Arcavi, an astronomer at Las Cumbres Observatory in California, highlighting the novelty of observing “multiple explosions in the same place.”
Typically, when stars experience supernova, they shine bright and then fade away, never to be seen again. However, iPTF14hls has rewritten this narrative.
Not only has it glowed for an astonishing 600 days, but its luminosity has fluctuated as much as 50 percent on an irregular basis. It appears as if it’s exploding repeatedly, in cosmic terms, winking at us across the vastness of space-time.
This bizarre behavior led Arcavi and his team to initially suspect that perhaps they were witnessing an optical illusion—a nearby Milky Way star blocking the supernova.
“I probably would have bet my car on it, but I’m glad I didn’t,” Arcavi admitted, reflecting on the surprising revelation that it was, in fact, the supernova itself that was the source of the phenomenon.
Upon further investigation, archival data revealed that an explosion had occurred at the very same location back in 1954, a historical echo suggesting that the star had somehow survived an earlier supernova event only to detonate once more in 2014.
The star’s oddity could represent the first known case of a Pulsational Pair Instability Supernova, a theoretical beast within the menagerie of celestial objects. Daniel Kasen from the University of California, Berkeley, who co-authored the study, proposed that this could be the outcome of a star so gargantuan and fiery that it forged antimatter in its core.
This would incite instability, triggering repeated luminous eruptions over several years, possibly even decades, before the star’s final explosive death throes and subsequent collapse into a black hole.
Yet, even with such a theory, the precise mechanics behind iPTF14hls’s light show remain elusive.
“As of now, no detailed model has been published that can explain the observed emission and constant temperature of iPTF14hls, let alone the possible eruption 60 years ago,” remarked Professor Stan Woosley from the University of California, who was not involved in the study.
The enigmatic supernova continues to offer astronomers “their greatest thrill: something they do not understand.”
Relevant articles:
– ‘Zombie star’ baffles astronomers after it survives FIVE supernova EXPLOSIONS, Daily Express