Free Astronomy Magazine November-December 2026

NOVEMBER-DECEMBER 2026 Strongest evidence yet that Betelgeuse has a companion by ESO Bárbara Ferreira A t long last, astronomers have firm evidence that Betel- geuse, one of the most fa- mous stars in the night sky, is not alone. Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), a team led by French re- searcher Miguel Montargès ob- tained the clearest image ever of what likely is Betelgeuse B, the star orbiting Betelgeuse. “This is the con- clusion of a century-long quest,” says Montargès. “We have shown that Betelgeuse is not single, it is accompanied by a faint stellar companion,” says Mon- targès, astronomer at the Observa- toire de Paris - PSL, France, and lead B etelgeuse is a red supergiant star in the Orion constellation. Its brightness changes periodically, and for decades astronomers had suspected that some of these variations could be due to a companion star orbiting around it. The image in the middle inset in this image was taken in January 2019 with the SPHERE instrument at ESO’s VLT, and shows Betelgeuse itself. The image in the inset on the left was taken in December 2024, when the companion was pre- dicted to be furthest apart from Betelgeuse as seen from Earth. In this inset Betelgeuse has been removed, revealing a source (marked with a crosshair) consistent with being Betelgeuse B. [ESO/M. Montargès et al. Background: N. Rissinger (skysurvey.org )] author of the study published in As- tronomy & Astrophysics . Betelgeuse — a reddish star in the Orion con- stellation that is easily visible with the naked eye and is known to change in brightness — has been ob- served for millennia. But it still sur- prises astronomers. “I jumped from my chair when I saw the processed images,” recalls Mon- targès. Astronomers have looked for the potential companion, originally proposed to explain Betelgeuse’s brightness changes, for about a cen- tury, but without success. Two stud- ies published in 2024 robustly pre-