Core Insights - The recent astronomical study published in the journal "Nature" reveals new insights into the internal structure of stars through the observation of a rare cosmic event, specifically a supernova explosion [1][2] - The research challenges existing theories regarding the mechanisms of mass loss and stripping in massive stars, suggesting the presence of a rare mechanism [2] Summary by Sections Study Findings - Astronomers observed supernova SN 2021yfj, which revealed that the progenitor star had shed most of its outer layers, exposing its internal stellar layers during the explosion [1] - A thick, massive shell rich in silicon and sulfur was detected, which was expelled shortly before the supernova event, alongside unexpected helium presence [1] Theoretical Implications - The findings directly confirm theoretical predictions regarding the shell structure of massive stars, extending to layers rich in silicon and sulfur, thus addressing the mystery surrounding the end of massive star life [2]