Astronomers have long searched for clues that a hidden companion star sits out of view near the red supergiant star Betelgeuse. Now, they’ve uncovered a new piece of evidence: a trail like the wake behind a boat, cutting through Betelgeuse’s upper atmosphere, likely forged by the unseen companion.Betelgeuse’s reddish tint can be spotted gleaming from the Orion constellation, situated about 650 light-years away from Earth.The bright star is so large that more than 400 million suns could fit inside of it. Its relative proximity and luminosity have made it a favorite among astronomers who observe and study the giant star’s evolution.AdvertisementAdvertisementAdvertisementAdvertisementYet, despite being so well known, Betelgeuse has its share of secrets — one of the biggest being why it appears to vary in brightness over a six-year cycle, and if the unseen stellar companion, nicknamed “Betelbuddy,” is responsible for this variability.Hints about the possible companion star were shared in research published last year, in which scientists suggested formally naming the object Siwarha, or “her bracelet,” an Arabic name befitting the companion to Betelgeuse, which means “Hand of the Giant.” (“Elgeuse” is also the historic Arabic name of the Orion constellation.)Siwarha would likely be too small and faint to be seen given its proximity to Betelgeuse, which has expanded as it has burned through all the hydrogen at its core, bringing it near the end of its life.Now, observations taken over the last eight years have revealed the effects of Siwarha on Betelgeuse: a never-before-seen dense trail of gas spotted moving through the larger star’s outer atmosphere, where Siwarha closely orbits.AdvertisementAdvertisementAdvertisementAdvertisementSiwarha’s trail appeared just after the star crossed in front of Betelgeuse from Earth’s perspective. Astronomers believe Siwarha completes one orbit around Betelgeuse every six years — hence the larger star’s change in brightness every six years. The observations are included in a new study that has been accepted for publication in the Astrophysical Journal.“It’s a bit like a boat moving through water. The companion star creates a ripple effect in Betelgeuse’s atmosphere that we can actually see in the data,” said lead study author Andrea Dupree, an astronomer at the Harvard-Smithsonian Center for Astrophysics, in a statement.“For the first time, we’re seeing direct sig …
