Scientists at Liverpool University have developed an early warning system that suggests that a red supergiant is approaching a supernova explosion.
In a study published in the Monthly Notices of the Royal Astronomical Society, astrophysicists analysed massive stars in the last phase of their lives, the stage of a red supergiant, and the analysis showed that the accumulation of material around the star caused it to darken shortly before the explosion.
So far, it has not been known how long it took a star to form this surrounding cocoon. For the first time, scientists modeled what red supergiants would look like just before the explosion.
Analysis of observations of existing supernovas showed that about a year before the explosion, the outer face of the star is no different than normal, which means that the cocoon is formed in just a few months, says the authors of the study, which is extremely fast by astronomical standards.
The bulk material closes the star almost completely, making it 100 times weaker in the visible part of the spectrum, which means that the day before the explosion, you probably won't be able to see that there was a star.
Scientists believe that using the new method, it is possible to pre-screen the supernova and observe it in real time, not just on the basis of the effects of the explosion.