Betelgeuse dimming explained by dust

Astronomers say they have solved the mystery of why Betelgeuse, one of the sky’s brightest stars, started getting dimmer in 2019. By mid-February this year, Betelgeuse had lost more than two-thirds of its brilliance — a difference noticeable to the naked eye. Some people speculated that this was a sign that the star was approaching the end of its life, but researchers working with the Hubble telescope now say it was probably caused by hot material that the star ejected into space, which then cooled and turned into dust.