'End of the century search': the strongest evidence yet of Betelgeuse's companion

A team of astronomers has confirmed the existence of a companion star to Betelgeuse, marking the end of a centuries-long search. Using the European Southern Observatory’s Very Large Telescope (VLT) and led by French researcher Miguel Montargès, the group captured the clearest image yet of what is believed to be Betelgeuse B, a dim star orbiting its massive red giant counterpart. The discovery was described as “the end of a century-long search” by Montargès, who emphasized that the findings prove Betelgeuse is not isolated but accompanied by a faint stellar companion. The search for Betelgeuse’s potential companion has spanned over a thousand years, with observers noting changes in the brightness of the famous star in Orion’s constellation. Despite this long history, astronomers have remained surprised by new discoveries even after such extended observation. Montargès, based at the Observatoire de Paris, PSL and leading the study, recalled how he felt upon seeing the processed images. He stated, “When I saw the processed images, I jumped on the table.” The team had been searching for a possible companion for nearly a century, but previous studies failed to yield conclusive results. In 2024, two separate studies suggested that Betelgeuse B might be closest to the main star in December of that year, making it easier to observe. This prompted Montargès and his team to begin their work using a specialized telescope at the observatory, followed by months of data analysis. Initially skeptical, Montargès admitted, “Honestly, I thought we didn’t have sensitive enough technology to detect Betelgeuse B.” However, the current research did not disappoint. The new observations reveal that Betelgeuse B is two to three times more massive than the Sun. According to Montargès, the fact that researchers can still discover a nearby companion, more massive and brighter than the Sun, around such a well-studied star is extraordinary. He called it one of the best moments in science: “Seeing something new and unexpected.” The finding adds to the growing body of evidence suggesting that Betelgeuse is part of a binary system, though further observations will be needed to confirm the companion’s presence definitively. Montargès expressed confidence that doubts would be minimal, stating there is little room for skepticism. The discovery could lead to future investigations into how this companion might influence the anticipated explosion of Betelgeuse. Such an event, known as a supernova, could have profound implications for our understanding of stellar evolution and cosmic phenomena. Montargès added, “We are also asking whether the companion might affect the development of the red supergiant.” As the scientific community continues to analyze these findings, the confirmation of Betelgeuse B represents a major milestone in observational astronomy. It underscores the power of modern telescopes and the persistence of researchers in uncovering the mysteries of the universe. With ongoing studies, scientists hope to gain deeper insights into the dynamics of this unique stellar pair and its potential impact on the fate of Betelgeuse.