Astronomers have finally discovered a long-sought companion to the bright red star Betelgeuse in the constellation Orion. The close-orbiting partner, which has been postulated for over a century, matches some predictions and adds another piece to the puzzle of the supergiant star.
The images, set to be published in the Astrophysical Journal Letters, show the faint companion but its detection is not yet confirmed. Leading astronomers agree that more instruments are needed to verify the discovery.
If confirmed, the new star would be named α Orionis B and could be referred to as Siwarha, meaning “her bracelet”, due to its association with Betelgeuse’s name. The companion orbits the supergiant at a distance just four times that between Earth and the sun, placing it within Betelgeuse’s expansive outer atmosphere.
The companion’s small size and rapid orbit make it vulnerable to being pulled into Betelgeuse within 10,000 years. Astronomers believe the star may have formed at the same time as Betelgeuse but its slow growth due to its smaller mass means it has not yet started fusing hydrogen.
This discovery is significant because it marks a first for astronomers, who have never seen such pairing of a supergiant and small companion before. The unique characteristics of Betelgeuse, including recent changes in brightness, led some to suspect the presence of a hidden companion.
Further observations will be made in November 2027, when the companion is at its farthest point from Earth.
Source: https://www.sciencenews.org/article/betelgeuse-companion-star-revealed