For roughly a century, astronomers suspected that Betelgeuse—the iconic red supergiant in Orion—might not be alone. Now, using advanced imaging technology, researchers have captured their strongest evidence yet of an orbiting partner: Betelgeuse B.
Solving a 100-Year Mystery
Betelgeuse’s brightness naturally shifts over time. A century ago, scientists theorized a secondary star might be pulling on it, causing some of those light swings. However, direct proof remained out of reach.
That changed when 2024 orbital models predicted the companion would reach its maximum separation from Betelgeuse in December 2024, opening a prime window to catch it.
Catching the Hidden Star
An international team led by French astronomer Miguel Montargès targeted Betelgeuse using the SPHERE instrument on the European Southern Observatory’s Very Large Telescope in Chile.
By applying processing techniques originally designed to hunt for faint exoplanets, the team filtered out Betelgeuse’s overpowering glare—revealing direct light from Betelgeuse B.
"I jumped from my chair when I saw the processed images," Montargès recalled. "Because it is more massive than predicted, we see it!"
Key Findings & What’s Next
- Heavier Than Expected: Astronomers thought the companion would match the Sun’s mass, but data shows it is 2 to 3 times more massive than the Sun.
- Brighter Appearance: Thanks to its extra mass, Betelgeuse B shines bright enough for direct imaging.
- Final Proof Pending: To confirm its orbit beyond doubt, researchers plan to observe the star again in a year when it reaches the opposite side of its path.
Discovering a star of this size gives astrophysicists a crucial new variable to consider when modeling Betelgeuse’s final evolution and its ultimate, spectacular supernova explosion.
Source: Science Daily
