Artwork: Betelgeuse is a red supergiant star, nearly 1,000 times larger than the Sun
Astronomers say big cool patches on a “supergiant” star close to Earth were behind its surprise dimming last year.
Red giant stars like Betelgeuse frequently undergo changes in brightness, but the drop to 40% of its normal value between October 2019 and April 2020 surprised astronomers.
Researchers now say this was caused by gigantic cool areas similar to the sunspots seen on our own parent star.
There had been speculation that Betelgeuse was about to go supernova.
But the star instead began to recover and by May 2020 it was back at its original brightness.
Betelgeuse, which is about 500 light-years from Earth, is reaching the end of its life. But it’s not known precisely when it