Scientists for the first time have observed the inner layers of a massive star as it exploded in the Milky Way in 2021. The event, called supernova 2021yfj, gave researchers an unusual chance to study how stars end their lives after burning fuel for millions of years. Normally, the violent blast of a dying star mixes up its structure, making the inside impossible to analyze. In this case, however, the star’s outer hydrogen and helium had already peeled away before the collapse, and even the dense layers of silicon and sulfur were stripped during the explosion. The study, published in Nature, was described as a breakthrough because it offered confirmation of long-standing theories about how stars are organized, with lighter elements on the outside and heavier ones near the core. Experts considered the observation an epochal moment in stellar research.

The team emphasized that this discovery not only gave evidence of stellar structure but also opened new questions. Astronomers debated whether the star lost its layers violently in the last stages of life or if a twin star removed them. The finding provided a lucid confirmation of scientific models, yet it also created conundrums that remain unresolved. Researchers said the event may be extremely hard to capture again, since such explosions are rare and unpredictable. Still, the work is expected to have a seminal role in understanding how supernovas spread elements that later become part of planets and life. Specialists also described the research as a monumental step forward in tracing the complex path of stellar evolution.