In 2012, a shrunken white star in a nearby galaxy reached the end of its life and exploded in a violent thermonuclear supernova. Such explosions – known as type 1a supernovae – are a common end for billions of stars in our universeusually resulting in the complete obliteration of the old star at the heart of the explosion.

But this time, something went wrong.

As the old star exploded from the inside out, the explosion did not reach the power and luminosity of a typical type 1a supernova. When the dust settled years later, scientists observing the stellar wreckage found that the old star hadn’t disappeared at all – it was still there, even bigger and brighter than before.

Somehow, the star had survived its own supernova explosion – a cosmic magic trick never seen before. However, in a study published in the The Astrophysical Journalresearchers are trying to explain how it happened.

Related: A strange ‘reverse shock wave’ supernova explodes in the wrong direction

“This surviving star is a bit like Obi-Wan Kenobi returning as a Force Ghost in Star Wars,” study co-author Andy Howell, assistant professor of physics at the University of California, Santa Barbara (UCSB ), said in a press release. “Nature tried to knock this star down, but it came back stronger than we could have imagined. It’s still the same star, but in a different form. It transcended death.”

The force awakens…

Astronomers first detected the supernova – named SN 2012Z – as its progenitor star was exploding. Using the Hubble Space Telescope, researchers observed the brilliant burst of light at the edge of a spiral galaxy some 120 million light-years away. Earthin the midst of a river of stars called the constellation Eridanus.

Based on its brightness and the type of light emitted, the explosion appeared to be a type 1a supernova – a thermonuclear explosion that would occur in star systems where the shrunken envelope of a scorched star, known as the white dwarf, shares a close orbit with another larger star. Scientists don’t know exactly how these explosions occur, but a popular theory suggests that the white dwarf gradually sucks gas from its companion star, until the white dwarf reaches a critical mass that triggers a runaway thermonuclear reaction in its core – resulting in a massive supernova explosion.

Subsequent observations in 2014 revealed that the supernova was stranger than astronomers had initially guessed. The explosion was much fainter and weaker than a typical Type 1a supernova, putting it in a rare category called Type 1ax supernova, or “failed” Type 1a supernova. But even more disconcerting, the researchers identified a white dwarf star at the exact epicenter of the explosion, shining even brighter than the progenitor star that had been there before.

It was the first time scientists had identified the progenitor star of a white dwarf supernova, the team wrote — and the first time a white dwarf star had apparently survived its own thermonuclear explosion.

“No one expected to see a brighter surviving star,” said the study’s lead author, Curtis McCully, a postdoctoral researcher at UCSB, in the statement. “It was a real headache.”

The best clue to solving this puzzle is the weakened nature of the type 1ax supernova, the researchers wrote. It’s possible that when the explosion went off, it was too small to completely blow out all of the gas that made up the white dwarf. Following the initial explosion, some of this material may have fallen back onto the partially exploded star, creating a zombie object called a bound remnant.

Counterintuitively, white dwarf stars have larger diameters when they have less mass, and become smaller as they become more massive, the researchers wrote. So when the bound remnant formed after the weakened supernova, it initially became larger and brighter than its progenitor white dwarf. Over time, the star will likely return to its original state, becoming smaller and denser, the team added.

Why the star failed to ignite into a typical Type 1a supernova remains a mystery. More research is needed to understand what gives a star the punch it needs to self-efface, and why others follow Obi-Wan’s path.

Originally posted on Live Science.