22-07-2025
Giant star Betelgeuse, visible to naked eyes, has a smaller sun orbiting it
Astronomers have achieved a historic breakthrough by directly detecting a hidden companion star in a remarkably tight orbit around Betelgeuse, the iconic red supergiant blazing in the constellation the innovative 'Alopeke instrument on the Gemini North telescope in Hawaii, one half of the International Gemini Observatory, researchers have solved a century-old mystery about Betelgeuse's puzzling brightness changes and opened a new chapter in understanding red easily visible to the naked eye and one of the largest stars near Earth, has captured human attention for millennia.
Its sheer size, some 700 times the Sun's radius, and fluctuating brightness have long made it a subject of fascination and confusion. Observations revealed that Betelgeuse's glow varies not only in a cycle of about 400 days but also in a pronounced secondary pattern every six years.
This discovery answers the millennia-old question of why this famous star experiences a roughly six-year-long periodic change in its brightness. (Photo: NOIRLab)
In 2019–2020, astronomers worldwide were riveted by the 'Great Dimming,' a sudden dramatic drop in the star's speculated Betelgeuse was about to explode in a supernova, but further analysis revealed the dimming resulted from a massive veil of dust cast off by the star Triumph: Direct Sight of a 'Betel-Buddy'Despite decades of pursuit and previous unsuccessful searches, including with the Hubble Space Telescope and Chandra X-Ray Observatory, no companion could be found until the recent by Steve Howell at NASA's Ames Research Center, the team utilised 'Alopeke's 'speckle imaging' technique: a method employing rapid-fire exposures that beat atmospheric blurring and deliver unparalleled coupled with Gemini North's immense 8.1-meter mirror, enabled the dim, tight-orbiting companion to finally come into the Companion StarAnalysis shows that the companion is six magnitudes fainter than Betelgeuse in visible light, and roughly 1.5 times the Sun's companiion is very young, classified as an A or B-type pre-main-sequence star, which is hot, blue-white, and not yet igniting hydrogen in its is orbiting just four times the Earth-to-Sun distance from Betelgeuse, well within the supergiant's extended atmosphere, an unprecedented finding.
Photo: NOIRLab
This is the first time such a close-in stellar companion has ever been detected around a supergiant star—a feat once deemed impossible to achieve with current discovery not only clarifies the underlying cause of Betelgeuse's six-year brightness variability but also hints that similar companions may shape the behavior of other red supergiants. Tidal forces will ultimately doom the companion, spiraling it into Betelgeuse over the next 10,000 prime opportunity to observe the companion will come in November 2027 when it will be at its greatest separation from Betelgeuse, promising more insights into the evolution of colossal stars.- Ends
