December 3, 2022

Betelgeuse Supernova Illustration

Massive stars warn that they are about to go to a supernova

Artist’s impression of a Betelgeuse supernova. Credit: European Southern Observatory / L. Calsada

Astronomers from Liverpool John Moores University and the University of Montpellier have created an ‘early warning’ system to sound an alert when a massive star is about to end its life in Supernova explosion. The work was published today (October 13, 2022) in Monthly Notices of the Royal Astronomical Society.

In this new study, the researchers determined that massive stars (typically between 8 and 20 solar masses) in the last stage of their lives, the so-called ‘red giant’ stage, will suddenly become about a hundred times fainter in visible light. The last few months before they died. This dimming is caused by a sudden buildup of material around the star, blocking its light.

Red giant stars are stars of the spectral type K or M with a giant luminosity class (Yerkes class I). In terms of size, they are the largest stars in the universe. However, it is not the most massive or luminous. Betelgeuse and Antares are the brightest and most famous giant red giants.

Until now, it was not known how long the star took to synthesize this substance. For the first time, scientists have now simulated what red giant planets might look like when embedded within pre-explosion ‘cocoons’.

Old telescope archives show that images do exist of stars that have exploded about a year after the image was taken. Stars appear naturally in these images, which means they cannot form a theoretical cocoon. This indicates that the cocoon is assembled in less than a year, which is considered very fast.

“The dense matter almost completely obscures the star, making it 100 times fainter in the visible part of the spectrum,” says Benjamin Davies of Liverpool John Moores University, lead author of the paper. This means that on the day before the star exploded, you likely wouldn’t be able to Seeing that he was there.” He adds, “Until now, we’ve only been able to get detailed observations of supernovae hours after they actually happen. With this early warning system, we can prepare to monitor them in real time, to point the world’s best telescopes at the precursor stars, and watch them scatter completely before our eyes.” “.

Reference: “An Imminent Explosion: The Emergence of Giant Red Giants at the Point of Fundamental Breakdown” by Ben Davies, Bertrand Blaise and Mike Pettrault, October 13, 2022, Available here. Monthly Notices of the Royal Astronomical Society.
DOI: 10.1093/mnras/stac2427