Supernovae: The Last Hours of the Observed Star

This was a primary supernova explosion. “For the first time we’ve seen a red giant explode! The activity of such a giant star has never been traced before it explodes in a Type II supernova,” says Jacobson-Gallan. On the basis of the numerous data, the working group was able to determine that the giant was about 5,000 K hot before its end and had 1,500 times the radius of our Sun. It was also ten times larger than our central star.

Amazingly, the dying star was still very active before its end, releasing massive amounts of radiation and matter. It was the first type II supernova to have such a high level of activity observed, Jacobson-Gallan & Co. wrote, otherwise the moments leading up to the corresponding supernova would have been much quieter. At least some giants behave differently than previously observed.

It is possible that the strong changes in the internal structure of the star, which caused the sudden supply of energy to the atmosphere, are responsible for this. Then it led to an increased production of stellar material, which was eventually observed. But it is not clear how this supply of energy came about. Gravitational waves from the fusion of neon and oxygen or a nuclear flash from the combustion of silicon can be considered. Astronomers write, but these are still hypotheses.