How Betelgeuse changed in brightness in 2019–2020

This animation combines four real images of the red supergiant star Betelgeuse, the first taken in January 2019 and the others taken in December 2019, January 2020 and March 2020, during the star’s unprecedented dimming. All images, which allow us to resolve the surface of the star, were taken with the SPHERE instrument on ESO’s Very Large Telescope.

Astronomers were puzzled to see Betelgeuse’s brightness decrease, but later found that it was caused by a “dusty veil” that partially concealed the southern part of the star.