Release of SPHERE data indicating the presence of a companion for Betelgeuse

Published: 19 Aug 2026

Betelgeuse is the most studied Red Super Giant. In 2024, through a reinterpretation of its long secondary period (LSP), a close orbiting stellar companion was suggested to exist, with a maximum elongation in December 2024. The goal was to search for this secondary component.

Observations were taken under programme 114.28H9 in extreme adaptive optics direct imaging with the Very Large Telescope SPHERE-ZIMPOL instrument by leveraging the pupil tracking mode of the telescope in angular plus spectral differential imaging (ASDI). Image processing was performed through ASDI PAtch Covariances (PACO ASDI) and principal component analysis (PCA).

The candidate Betelgeuse B was detected at 6.1σ with PACO ASDI and at 5.1σ with PCA in the CntHa filter on December 6, 2024. The separation is 52.32 ± 0.18 mas, and the position angle is 117.12 ± 0.60°. Assuming the two stars are coeval, the companion is a 2.6 to 3.1 M young main-sequence star. More information are available in the research paper.

The accompanying release documentation describes the data that are available for download via the Archive Science Portal or programmatically.

The DOI associated to this data collection is doi.org/10.18727/archive/114.