Betelgeuse's hidden companion leaves a wake in its atmosphere

New radio observations show Siwarha, the small companion of red supergiant Betelgeuse, ploughing through the star's extended atmosphere and leaving a wake. Using 2021-2026 data from the Very Large Array and ALMA, MIT Haystack researchers found the atmosphere stretches into an egg shape when the companion is farthest away. The data also show Betelgeuse has largely recovered from its 2020 'Great Dimming'.