Scientists claim to have solved the mystery behind why one of the brightest stars in the sky suddenly became visibly darker.
Betelgeuse, a red supergiant located in the constellation of Orion, lost more than two-thirds of its light back in 2019.
The incident sparked fears that the star was coming to the end of its life and could be about to explode.
But the dimming only lasted for a few months before the star returned to its original level of illumination in April 2020, reported Sky News.
The sudden changes left astronomers puzzled and some researchers teamed up to figure out what had caused it.
Using the European Southern Observatory’s and Very Large Telescope (VLT) to analyse images of the supergiant, researchers found that a cloud of stardust was the cause.
They also found that the event was triggered by the formation of stardust obscuring half of Betelgeuse, reported the broadcaster.
Miguel Montarges, from the Observatoire de Paris, France, and KU Leuven, Belgium, who is lead author on the study, said: “For once, we were seeing the appearance of a star changing in real time on a scale of weeks.
“We have directly witnessed the formation of so-called stardust.”
Scientists believe that Betelgeuse ejected a large gas bubble during the dimming.
Shortly afterwards, as the surface of the star partially cooled, heavier elements in the gas, such as silicon, condensed into solid dust, according to Sky News.
Professor Stefan Kraus from the University of Exeter, one of the study authors, added: “Ageing stars such as Betelgeuse have long been suspected to churn out flecks of dust, either through a constant wind or more localised surface ejections.