Astronomers from Liverpool John Moores University and the University of Montpellier have developed an ‘early warning’ system to give warning when a massive star is about to end its life in a supernova explosion. The book was published in Royal Astronomical Society Monthly Notices.
In this new study, the researchers determined that massive stars (usually between 8 and 20 solar masses) in the last phase of their life, the so-called ‘red supergiant‘, will suddenly become a hundred times weaker in visible light in the last months before their death. This darkening is caused by a sudden buildup of material around the star, which obscures its light.
Until now, it was not known how long it took for the star to accrete this material. Now, for the first time, researchers have simulated what red supergiants might look like when embedded in these pre-explosion “cocoons.”
Old telescope records show that there are images of stars that exploded about a year after they were taken. The stars appear normally in these images, which means that they may not have constructed the theoretical circumstellar cocoon yet. This suggests that the cocoon is assembled in less than a year, which is considered extremely fast.
Benjamin Davies of Liverpool John Moores University and lead author of the paper, says: “The dense material obscures the star almost completely, making it 100 times fainter in the visible part of the spectrum. This means that, on the eve from the exploding star, you probably wouldn’t be able to see it was there.” He adds: “Until now, we have only been able to obtain detailed observations of supernovae hours after they have already occurred. With this early warning system, we can prepare to observe them. real timeto point the world’s best telescopes at the precursor stars and watch them literally rip apart before our eyes.”
Ben Davies et al, Imminent explosion: the appearance of red supergiants at the point of core collapse, Royal Astronomical Society Monthly Notices (2022). DOI: 10.1093/mnras/stac2427
Royal Astronomical Society
Quote: Red Alert: Massive stars sound warning they are about to go supernova (October 13, 2022) retrieved October 13, 2022 from https://phys.org/news/2022-10-red-massive-stars-supernova.html
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