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For the first time, the end of a very massive star might be observed, before its explosion in a supernova. Moments less peaceful than what had been envisaged.
An artist’s impression of a red supergiant star in the last year of its life here emitting a tumultuous cloud of gas.
Observatoire W.M. Keck/Adam Makarenko
For the very first time, astronomers have been able to capture in real time the end of the life of a red supergiant, a type of very massive star. Using the télescope W.M. Keck from Maunakea, Hawaii, the team – made up of astronomers from Northwestern Universities (Illinois) and Berkeley (California) – was able to follow for 130 days, during the summer of 2020, the star’s rapid self-destruction massive and its last jolts before its collapse into a type II supernova. The sighting is reported in an article by «The Astrophysical Journal» dated January 6, 2022.
Previous examinations had shown that the red supergiants were relatively calm before their death, with no evidence of violent eruptions or light emissions. The new observations, however, have detected light radiation from one of these stars in the last year before it exploded. This suggests that at least some of them must undergo significant changes in their internal structure.
Also violent activity “never confirmed”
“This is a breakthrough in our understanding of what massive stars do moments before they die,” study lead author Wynn Jacobson-Galán said in a statement from the Keck Observatory. “Direct detection of pre-supernova activity in a red supergiant star has never been observed before in an ordinary Type II supernova. For the first time, we have witnessed the explosion of a red supergiant star. ”
In the same statement, Raffaella Margutti, co-author of the paper, said: “It’s like looking at a time bomb. We have never confirmed such violent activity in a dying red supergiant – a supergiant that we have clearly seen emitting light, collapsing and burning. ”
(vja)