Stellar Wake Uncovers Betelgeuse's Secret Partner

Astronomers have identified a unique gas trail within Betelgeuse's outer atmosphere, serving as the most significant evidence yet for an unseen companion star. This dense wake, observed over eight years, is thought to be created by the companion, tentatively named Siwarha, as it completes an orbit around the massive red supergiant. The timing of Siwarha's orbit aligns with Betelgeuse's observed six-year cycle of brightness variation, suggesting a direct causal link. Previous research had hinted at Siwarha's existence, but this new discovery provides visual confirmation of its impact.

The observations, utilizing data from the Hubble Space Telescope and ground-based observatories, reveal how Siwarha's passage stirs Betelgeuse's extended atmosphere. This "ripple effect" in the gas and dust is crucial for understanding the supergiant's behavior and luminosity changes. Scientists believe Siwarha, much smaller than Betelgeuse, is being pulled closer by gravity and may merge with its larger companion within 9,000 years, potentially before Betelgeuse undergoes its supernova.

Understanding Betelgeuse's variations, including its past "Great Dimming" event, helps astronomers study other distant giant stars. The interaction with Siwarha is key to interpreting Betelgeuse's evolution, material shedding, and eventual supernova. Future observations, expected to include Siwarha becoming visible from Earth around 2027, aim to refine orbital data and mass estimations for both stars, furthering our understanding of binary systems and stellar physics.