Dimming of Betelgeuse. Comparison of images taken in January (left) and December (right) 2019, showing how the red supergiant star has faded and how its apparent shape has changed. Betelgeuse is about eight million years old and on the verge of becoming a supernova. It is one of the largest stars currently known, with a radius around 1400 times larger than the Sun's. Observations taken with the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument on ESO's Very Large Telescope (VLT).