New Images Provide the Best Evidence Yet That Supergiant Star Betelgeuse Does, Indeed, Have a Long-Theorized Stellar Companion

The research team is mostly convinced by the data, but they want to capture additional observations in 2027 to confirm what they’ve found

Sara Hashemi | Daily Correspondent

August 3, 2026 4:07 p.m.

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Astronomers have long speculated that Betelgeuse—one of the brightest stars in the night sky—is not alone. Now, they’ve captured the best evidence yet that it’s orbited by an elusive stellar companion.

The sighting happened in December 2024, when the theorized companion star was predicted to be at its farthest point from Betelgeuse, as distant as possible from its bigger sibling’s limelight as seen from Earth—and therefore easier to see. The findings, published in the journal Astronomy and Astrophysics on July 28, could help scientists better understand Betelgeuse’s evolution and provide a long-awaited answer.

“We have shown that Betelgeuse is not single; it is accompanied by a faint stellar companion,” says study co-author Miguel Montargès, an astronomer at the Paris Observatory, in a statement. “This is the conclusion of a century-long quest.”

Located roughly 550 light-years from Earth in the constellation Orion, Betelgeuse is a red supergiant star about 16.5 to ​19 times as massive as our sun and about 100,000 times as bright. It’s one of the most-studied stars in the Milky Way, yet one aspect of it has remained mysterious. For more than 100 years, researchers have proposed that the star has an unseen stellar companion that would explain certain quirks in its behavior, such as certain periodic variations in its brightness.

In 2025, a different research team reported a faint image of a possible companion star orbiting Betelgeuse. The data, however, was inconclusive, and outside researchers wanted additional observations.

“I think at this point it’s quite tough to say whether or not the detection is believable,” Sarah Blunt, an astrophysicist at the University of Colorado Boulder who was not involved with the study, told Science News’ Mara Johnson-Groh last year. “We’ll have to wait and see if the companion can be confirmed with more instruments.”

Even so, the authors of that study proposed that the potential companion be named Siwarha, which means “her bracelet” in Arabic, to reference Betelgeuse’s name, which translates to “hand of the giant.” That’s now the formal title.

In the new study, Montargès and his colleagues used the Very Large Telescope in Chile to spy on the supergiant star for two nights in early December of 2024. They relied on a powerful instrument created to find exoplanets by blocking out a host star’s light, helping researchers snapshot dim orbiting objects. Like those exoplanets, Siwarha’s light is almost completely drowned out by Betelgeuse’s glare.

Analyses of the observations hint that the stellar companion is 2.6 to 3.1 times as massive as our solar system’s star—more than originally expected, says study co-author Andrea Dupree, an astronomer at the Harvard-Smithsonian Center for Astrophysics, to Lisa Grossman at Science News. Researchers thought it would have about the same mass as our solar system’s star.

The team estimates that the companion completes a trip around Betelgeuse roughly every six years, a finding that is consistent with recently proposed theoretical models. But the true test will come in 2027.

“To be certain that the companion is really there, we still need to observe it in one year on the other side of the star,” Montargès says in the statement. “But there is very little space left for doubt.”

Still, he’s “very conservative” about the new results and “keeps calling it a candidate,” Dupree tells Science News. She and some other team members, however, are mostly convinced that what they saw is real. “We say it’s really there.”  

The discovery could help astronomers better understand the fate of Betelgeuse, thought to be near the end of its lifetime. When it was considered a loner, researchers estimated that the supergiant would explode as a supernova sometime within the next 10,000 to 100,000 years, Montargès tells Reuters’ Will Dunham. 

“Now that we know that it has a companion that could be interacting with it, I must say that I ⁠don’t know ​when it will explode,” he adds. “If the two stars have interacted or will interact, it ​could delay or accelerate the supernova. We cannot be sure of anything anymore regarding this star.”

Sara Hashemi is a science writer and fact-checker currently based in New York City. Her work has appeared in Sierra, The Body, Maisonneuve magazine and more.