Scientists observe a red supergiant going supernova for the first time

Despite the large number of stars in the sky, spotting one in the throes of a supernova is very rare. Astronomers have captured a red supergiant before, during and after a supernova explosion, gathering crucial new information.

"This is a breakthrough in our understanding of what massive stars do moments before they die," said lead author Wynn Jacobson-Galn. Pre-super nova activity in a red supergiant star has never been observed before in an ordinary type II supernova. We watched a red supergiant star explode for the first time.

The doomed red supergiant star was detected by the Pan-STARRS telescope in Maui, Hawai'i, in the summer of 2020. The team captured the powerful flash using the LRIS. The first spectrum of the supernova was captured by them.

The observations show that the star ejected a lot of material just before the explosion. The new data shows that red giants were relatively calm before exploding, so it suggests that some may change their internal structure. That could cause gas ejections moments before the collapse.
It was about 10 times larger than the Sun and was located in the NGC 5731 galaxy. When stars run out of fuel, they collapse on their own gravity and cause a massive carbon fusion explosion. They must be large enough to collapse into a white dwarf star like our Sun will eventually do. They could collapse into a black hole if they were larger than that.
The discovery will allow scientists to look for similar types of radiation that could signal another supernova. The quest to solve the mystery on how massive stars spend the final moments of their lives will be impacted by detecting more events like SN 2020tlf.