A giant star 150 times bigger than the Sun has been pictured ‘hiccuping’ by scientists.
Despite being predicted in theory, the rare cosmic event had never been seen before. It only occurs in enormous stars 60 to 150 times larger than our Sun.
Confirming the existence of “hiccuping” stars is a huge leap forward in understanding how larger stars work and how they shape the universe, researchers have said.
Dr Charlotte Angus, from the Astrophysical Research Centre (ARC), and her team tracked a supernova using telescopes from around the world and documented “Pulsational Pair Instability” (PPI), when the core increases in temperature then contracts and expands in the final years of their lives, The Independent reports.
Each pulse kicks off a small piece of shell material, which strips the star’s core. These shells can collide and create bursts of light – this was seen by the researchers. The star underwent a series of extreme pulses in the 50 days before it exploded.
When they saw the star for a second time, it was expanding quickly, suggesting it had exploded, ending its life.
Dr Angus said the collisions are much less bright than the final supernova explosion, meaning it had previously not been possible to confirm the theory.
She added: “In December 2020, we identified a new bright supernova, now named ‘SN2020acct’, in a nearby spiral galaxy called NGC 2981. The light from SN2020acct disappeared pretty quickly.
“But then in February 2021, we saw light coming from the same region of the galaxy again. This is very unusual as supernovae normally don’t reappear.
“This is the first time that we have ever obtained observations of a PPI candidate during the shell collisions, allowing us to confirm for the first time that this is really happening.
“That the data matches the modelling predictions is incredibly exciting.”
Also involved in the project were astronomers from the University of California Santa Cruz and from three recent surveys – the Young Supernova Experiment, the ATLAS survey and the PanSTARRS survey.
