Betelgeuse has long captured our imaginations—and now astronomers have uncovered a hidden partner in its cosmic dance, one 1.5 times the mass of our Sun!
The Great Dimming That Sparked a Mystery
Back in late 2019, Betelgeuse stunned skywatchers by dimming dramatically. For months, we all wondered if we were witnessing its final supernova act. It turns out the dip in brightness wasn’t the star’s death knell but a colossal dust cloud it had expelled. That finding reignited interest in this red supergiant—already famous for its sheer size, with a radius 700 times that of the Sun.
Betelgeuse burns red; Rigel shines blue — Orion leads the way. pic.twitter.com/wVP6qkSHGv
— Milky Way Astronomers✨ (@fascinatingonX) July 7, 2025
Hunting for a Companion Star
Astronomers noticed Betelgeuse’s light flickered on two cycles: a 400-day heartbeat and a much slower six-year rhythm. A nearby companion seemed a likely culprit, yet Hubble and Chandra saw nothing.
Alopeke’s Breakthrough
Enter Alopeke, a high-speed imager on Gemini North’s 8-meter telescope in Hawaii. By freezing Earth’s atmospheric blur, Alopeke finally revealed Betelgeuse’s secret companion. This newly spotted star is an A- or B-type pre–main-sequence object—hot, blue-white, and still igniting hydrogen in its core. Though six magnitudes fainter, it orbits just four astronomical units from the supergiant, literally inside Betelgeuse’s outer atmosphere.
A Companion Destined for Doom
This is the first time anyone has imaged a close stellar companion to a supergiant. Models said it couldn’t be done, but Alopeke proved them wrong.
Born together, the two stars share a destined dance: tidal forces will eventually drag the smaller star inward, consuming it in roughly 10,000 years.
Looking Ahead to the 2027 Reunion
To see this companion again, astronomers must wait until November 2027, when its orbit carries it to maximum separation—ideal for imaging. Scientists eagerly plan to watch Betelgeuse before and during that next close approach to unlock more secrets of this stellar duo.
Nathalie Mayer
Journalist
Born in Lorraine on a freezing winter night, storytelling has always inspired me, first through my grandmother’s tales and later Stephen King’s imagination. A physicist turned science communicator, I’ve collaborated with institutions like CEA, Total, Engie, and Futura. Today, I focus on unraveling Earth’s complex environmental and energy challenges, blending science with storytelling to illuminate solutions.
