American astronomers observed for the first time in real time the dramatic explosive end of the life of a red giant star, recording its self-destruction and eventual death, shortly before it collapsed gravitationally and created a supernova type (supernova) type II.
Scientists have been able to observe the star for the last 130 days before its cataclysmic eruption. The star is located in the galaxy NGC 5731 at a distance of about 120 million light-years from Earth and has a mass ten times that of our Sun.
Researchers at the University of Northwestern and the University of California-Berkeley, who published their findings in The Astrophysical Journal, made their observations using two Hawaiian telescopes, the Keck and the Pan-STARSS. The discovery brings a revision of previous theories about how red giants evolve shortly before they explode. There was a perception that these huge stars remained relatively quiet before their death, without violent explosions or flashes of light, but new observations showed the emission of a very strong and bright radiation, just before the end of this star. This shows that at least some of these huge and unstable stars undergo significant changes in their internal structure shortly before their collapse.
“It’s a big step forward in our understanding of what oversized stars do a few moments before they die. “Immediate detection of pre-supernova activity in a red supergiant star had never been observed before a normal Type II supernova explosion.
“It’s like watching a time bomb. “We have never before witnessed such violent activity on a dying red supergiant, which we have seen produce such a luminous emission of radiation, after it collapses and explodes,” said Rafiat North, an associate professor of astronomy and astrophysics.