Chinese scientists make breakthrough in decoding supernova explosion

Chinese scientists have captured the spectacular moment when the explosion shock wave of supernova (SN) 2024ggi broke through the surrounding dense circumstellar material (CSM), offering crucial insights into unraveling the mysteries of late-stage stellar evolution and death.

According to the Yunnan Observatories under the Chinese Academy of Sciences (CAS), the study enhanced the understanding of the initial stages of SN explosions and shock propagation through the asymmetric stellar surroundings. The related findings were published in The Astrophysical Journal Letters.

The SN 2024ggi is located about 20 million light-years from Earth. Zhang Jujia, a researcher at the Yunnan Observatories, showed China Media Group (CMG) an image they took of the supernova. "It's in a galaxy, and it looks like a star," said Zhang.

The supernova explosion is a very violent celestial event that usually occurs at the end of a star's life cycle. It releases so much energy which can even outshine entire galaxies for a short time. The "shock breakout" is the earliest electromagnetic radiation event following a supernova explosion, which can reveal the extreme physics during a star's death throes.

The research team utilized advanced astronomical equipment such as the 2.4-meter Lijiang Telescope of Yunnan Observatory, the 10-meter Very Large Telescope of the European Southern Observatory, the 3.6-meter Telescopio Nazionale Galileo in Italy, and the 6.5-meter Magellan-Baade Telescope at Las Campanas Observatory to conduct continuous high-cadence spectral monitoring of this SN during the initial few tens of hours after the explosion.

Eventually, they captured the shock breakout signal, revealing the complex shock wave propagation of SN 2024ggi. "Through this series of spectrum, we can reconstruct how the material outside the supernova was distributed. So we can figure out what a massive star like this is going to look like in its final evolution stages," said Zhang.

According to the introduction from experts, the stars have existed since the beginning of the universe. They end their lives in the last moment of life with the brilliance that lights up the entire galaxy, resulting in a large number of heavy elements, including gold. Therefore, in a sense, gold is also a true cosmic fragment.

"Elements heavier than iron can only be produced by supernova explosions. So gold, silver are produced by supernovae. They are blasted out into the universe here and there and then later condensed back together," Zhang added.