When a star explodes, it usually takes it 100 days to die off completely. However, scientists have recently stumbled upon a true zombie star which keeps getting brighter, although it exploded in 2014. This discovery changed everything they knew about supernovas, showing they don’t always behave the same.
The zombie star keeps getting dimmer and brighter, but it doesn’t fade away
In 2014, researchers observed a star situated 500 million light-years away from Earth. They spotted it as soon as it exploded and, as time went on, it looked like a typical supernova, meaning that it kept getting less bright over time. However, something strange happened.
After a few months, when they looked at the star again, they saw how, instead of fading, it became brighter. Usually, a supernova fades away completely in about 100 days. Over 1,000 days have passed since this object exploded, and it’s still bright. In fact, it undergoes two stages. After shining bright, it starts fading slowly, and then starts shining again.
Scientists offered several possible explanations for the phenomenon
This unusual behavior of zombie star baffled the scientists, who have never seen a supernova to last for so long. Even if they witnessed so many of these phenomena, they still manage to get surprised from time to time. Iair Arcavi, one of the researchers which studied the zombie star, would never have thought something like this could happen.
“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.”
Researchers offered a series of explanations which could have caused the event. They suggested that the event could have been made up of a series of explosions quickly following one another, leading to the progression of the bright and dim phases. Also, it could have been only one big explosion which switched from bright to dim and so on.
A third explanation says the zombie star was a lot bigger than our sun. This means that, when it exploded, the supernova blew all its outer layers away, but the core was untouched. This allowed it to repeat the explosions, thus displaying so many brightness switches.