Betelgeuse has a companion star, and astronomers have a photo
Astronomers have confirmed that the red supergiant star Betelgeuse has a small, blue companion star. The discovery was made using the SPHERE instrument in Chile, which successfully captured the companion after decades of searching.
Why it matters
This finding resolves a long-standing mystery regarding the star's complex brightness cycles and improves our understanding of stellar evolution.
Betelgeuse, the orange star in Orion’s shoulder, has a companion. The second star is small and blue, and it orbits close enough to pass through the supergiant’s dust.
Astronomers had searched for a century and found nothing.
Dr. Miguel Montargès of the Observatoire de Paris and his colleagues photographed it in December 2024 with the Very Large Telescope in Chile.
“For a regular observer, the discovery changes nothing when looking at Orion,” Dr. Montargès told Earth.com.
Orion appears in cave paintings, and the constellation is visible from both hemispheres. Dr. Montargès said all of humanity has watched this star.
“I find it incredible that we still discover something as fundamental as its binarity in 2026,” he added.
Betelgeuse brightens and fades on four separate schedules: roughly 180, 230, 420 and 2,200 days. The three quick ones are the star swelling and shrinking.
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