Scientists recently achieved something remarkable: they captured the moment a supernova’s shockwave burst through the surface of a dying star. This event, known as SN 2024ggi, occurred on April 10, 2024, in a galaxy called NGC 3621, located about 22 million light-years away in the constellation of Hydra.
Yi Yang, an astronomer from Tsinghua University in Beijing, and his team jumped into action when they learned of the explosion. They managed to get time on the Very Large Telescope in Chile just 26 hours after the supernova was detected by the Asteroid Terrestrial-impact Last Alert System.
The first observations were crucial; they showed a moment when material from the star, accelerated by the explosion, shot outward. Dietrich Baade from the European Southern Observatory noted that this phase allowed astronomers to observe both the star and its explosion together.
The star that exploded was a red supergiant, about 12 to 15 times the mass of our Sun. These massive stars reach the end of their life when they can no longer perform nuclear fusion, leading to a collapse that sends their outer layers outward in a tremendous explosion. The star took about a day to visibly show this shockwave due to its enormous size.
Missing this moment would have meant losing vital information about how stars explode. This data is essential for understanding stellar evolution.
Using a technique known as spectropolarimetry, the team analyzed the light from the explosion. This method revealed the shape of the breakout was somewhat flattened, much like an olive, but interestingly, it also showed that the explosion remained symmetrical even when it encountered surrounding materials.
Yang emphasized that these findings suggest a common mechanism for the explosions of many massive stars, emphasizing their symmetry on a large scale. This was a significant revelation because it helps scientists rule out certain models of supernovae while supporting others.
Some theories propose that supernovae can gain energy from tiny particles called neutrinos as they erupt. But since SN 2024ggi displayed a symmetrical explosion, it contradicts the idea that neutrinos are key in creating asymmetrical explosions. Instead, the team suggests that powerful magnetic fields may play a role in these asymmetric events.
The findings from SN 2024ggi were published in Science Advances. This research not only deepens our understanding of supernovae but also opens doors for future investigations into the dynamics of stellar explosions.
For more details about the research, you can read the full paper on the ESO website.
