Scientists were able to observe the star during the last 130 days before its cataclysmic explosion. The star is located in the galaxy NGC 5731 about 120 million light-years from Earth and has a mass ten times that of our Sun.
The Northwestern and California-Berkeley University researchers, who published the paper in the astrophysical journal The Astrophysical Journal, made their observations with two Hawaii-based telescopes, Keck and Pan-STARSS. The discovery brings a revision to previous theories about how red giants evolve just before they explode. There was a perception that these massive stars remain relatively quiet before their death, with no violent explosions or bright flashes, but the new observations have shown the emission of a very powerful and bright radiation just before the end of this particular star. This shows that at least some of these massive and unstable stars undergo significant changes in their internal structure just before they collapse.
"This is a major advance in our understanding of what supermassive stars do moments before they die. The direct detection of pre-supernova activity in a red supergiant star had never before been observed before a normal Type II supernova explosion. For the first time we have watched a red supergiant star explode," said lead researcher Win Jacobson-Galan of Berkeley.
"It's like watching a time bomb. Never before had we confirmed such violent activity in a dying red supergiant, which we saw produce such a bright emission of radiation, then collapse and explode," said Northwestern associate professor of astronomy and astrophysics Raphaela Marguti of Northwestern.
Link to scientific publication: https:/iopscience.iop.org/article/10.3847/1538-4357/ac3f3a
Source: Cyprus Times
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