Astronomers from Liverpool John Moores University and the University of Montpellier have created a "early warning" system that can predict when a massive star will die in a supernova explosion. The paper was published in the Royal Astronomical Society's Monthly Notices.

Stars


Researchers established in this new study that large stars (usually between 8 and 20 solar masses) in their last phase of life, known as the'red supergiant' phase, will abruptly become roughly a hundred times fainter in visible light in the last few months before they die. The dimming is produced by a rapid buildup of material surrounding the star, which obscures its brightness.

Read More — What Exactly Is a Meteor Shower?

It was previously unknown how long it took the star to accumulate this stuff. For the first time, scientists have modelled how red supergiants would seem when buried within these pre-explosion 'cocoons.'

supernova


Old telescope archives include images of stars that burst around a year after the snapshot was taken. The stars seem normal in these photos, indicating that they have not yet formed the hypothesized circumstellar cocoon. This means that the cocoon is created in less than a year, which is considered extremely fast.

The paper's principal author, Benjamin Davies of Liverpool John Moores University, states "The thick debris nearly entirely obscures the star, making it appear 100 times fainter in the visible spectrum. This implies that you wouldn't be able to view the star the day before it bursts." He continues, "Until recently, scientists could only acquire comprehensive views of supernovae hours after they occurred. With this early-warning system, we can prepare to see them in real time, pointing the world's greatest telescopes toward the precursor stars and watching them physically split apart in front of our eyes."

Read More — What is greater in size than the Sun?

Read More — What is the Sun Made of?