For the first time, astronomers have observed the inner workings of a dying star during its explosive transition into a supernova, providing invaluable insights into the processes of stellar evolution. Stars can have lifespans ranging from millions to trillions of years, eventually exhausting their fuel and ending their lives in spectacular supernova explosions. Observing these explosions has been challenging, as they often disrupt a star’s layered structure, complicating the study of their interiors.
The supernova in question, designated 2021yfj, is situated within our Milky Way galaxy. Remarkably, the research team managed to observe not only the typical outer layers of hydrogen and helium shedding away but also the dense inner layers of silicon and sulphur being stripped during the explosion. Steve Schulze, a member of the discovery team from Northwestern University, noted the unprecedented extent of this stripping, stating, “We have never observed a star that was stripped to this amount.”
This discovery provides critical evidence supporting the theoretical models of massive stars nearing the end of their life cycles, which suggest that lighter elements reside in the outer layers while heavier elements are concentrated towards the core. Anya Nugent, a supernova researcher at the Harvard-Smithsonian Centre for Astrophysics, explained that the significant loss of layers from 2021yfj confirms the expected structure of such stars.
The exact process that led to this unique condition remains uncertain; researchers are investigating whether the layers were violently ejected during the star’s final moments or stripped away due to the gravitational influence of a companion star. Future studies are anticipated to shed more light on these phenomena, although capturing similar occurrences may prove to be a rare challenge.
Overall, this observation not only enhances our understanding of the life cycle of massive stars but also opens new avenues for research into stellar dynamics and the ultimate fates of these celestial objects.