Astronomers have made a groundbreaking discovery regarding the shape of a supernova, marking the first time such a phenomenon has been mapped immediately after its explosion. The supernova, designated SN 2024ggi, occurred in the galaxy NGC 3621, located approximately 22 million light-years away in the constellation Hydra. The findings were shared on November 12, 2025, in the journal Science Advances.
The explosion was first detected on April 10, 2024, by the Asteroid Terrestrial-impact Last Alert System (ATLAS), which captured the initial light from the massive star’s demise. With a mass approximately 12 to 15 times that of the Sun, SN 2024ggi offered astronomers a rare opportunity to study the initial stage of a star’s life cycle. Just 26 hours later, scientists directed the Very Large Telescope (VLT) in Chile to observe the supernova, taking advantage of a brief window that allowed them to analyze the explosion’s early shape.
Utilizing a technique known as spectropolarimetry, which categorizes light by its wavelengths and reveals its vibrational direction, researchers captured the unique shape of the supernova. Data from the VLT’s FORS2 instrument indicated that the initial light emitted from the explosion was not uniform in all directions. Instead, it exhibited a distinctive elongated form, reminiscent of an olive, suggesting the explosion was not perfectly spherical.
As the supernova expanded, astronomers observed its interaction with the surrounding gas. By approximately day ten post-explosion, the hydrogen-rich outer layers of the star became visible. These layers aligned with the same axis as the initial shock, indicating that the core explosion maintained a stable, directional shape from the outset. This observation points to an underlying mechanism responsible for the consistent orientation of the supernova’s explosion.
The research challenges some existing models of supernova formation while supporting others, shedding light on the catastrophic end of massive stars. This unprecedented view into the supernova’s dynamics provides valuable insights into the processes governing stellar explosions, which have long been a topic of scientific debate.
The study’s findings are significant not only for understanding the life cycle of stars but also for the broader implications they hold for astrophysics. As scientists continue to explore the cosmos, discoveries like that of SN 2024ggi highlight the intricate and dynamic nature of the universe, as well as the technological advancements that enable such observations.
