Supernova (SN) 2020tlf, identified by red markers, in the act of exploding 120 million light years away. The bright white region to the upper right is the crowded center of the star’s galaxy, the oval-shaped NGC 5731. This direct image was captured using the Pan-STARRS camera at the Haleakala Observatory, Hawai’i.  It shows the supernova in optical light. (Pan-STARRS/YSE)

When a large star reaches the end of its life it runs out of fuel, collapses and explodes into a supernova. The explosion releases enormous amounts of energy and light, turning a luminous object that is small at a distance into a large glowing ball.

Supernova temperatures have been modeled to reach 6,000 times higher than the core temperature of our Sun. Much of the matter in the star is sent flying into space and, in moments, the gigantic eruption is over. These cataclysmic events — the most energetic explosions ever seen by humans — are known to send far into the cosmos shock waves of compressed gas clouds that eventually birth new stars.

Supernova are stupendous astrophysical events which are of great interest to astronomers.  And over the past several years an international team including the University of California, Berkeley and the University of Hawai’i  have actually captured such an explosion of a red supergiant star — the first such imaging of its kind.

“For the first time, we watched a red supergiant star explode!” said Wynn Jacobson-Galán, a National Science Foundation Graduate Research Fellow at UC Berkeley and lead author of the study in The Astrophysical Journal. “This is a breakthrough in our understanding of what massive stars do moments before they die.”

“It’s like watching a ticking time bomb,” said senior author Raffaella Margutti, an associate professor of astronomy at UC Berkeley, and one of those who monitored the star for several months before it exploded.

“We’ve never confirmed such violent activity in a dying red supergiant star, where we see it produce such a luminous emission then collapse and combust. Until now.”

An artist’s video rendering of a red supergiant star transitioning into a Type II supernova, emitting a violent eruption of radiation and gas on its dying breath before collapsing and exploding.  (W. M. Keck Observatory/Adam Makarenko)

A supernova of the type and size of the one just observed are known to occur periodically,  but predicting when massive stars will reach that final violent stage and having telescopes in place to observe it has been a bridge too far.… Read more