# Betelgeuse companion discovery

> Live situation record from CLSTR: https://clstr.news/situations/betelgeuse-companion-discovery
> Updated: 2026-08-02T07:12:00.000Z. Sources: 25. Developments: 3.

In late July 2026, astronomers using the European Southern Observatory’s Very Large Telescope in Chile announced the first clear image of a faint star orbiting the red supergiant Betelgeuse. The companion, designated Betelgeuse B, was captured with the SPHERE high‑contrast instrument during the December 2024 window when its separation from the primary was greatest. Measurements placed the object about 8.8 AU from Betelgeuse and estimated its mass at two to three times that of the Sun, matching the six‑year brightness‑variation cycle that has puzzled observers for a century.

A subsequent report a few days later reaffirmed the finding, highlighting stronger evidence for a massive companion and noting plans for follow‑up observations as the star moves to the opposite side of its orbit.

On 2 August 2026, a study published in *Astronomy & Astrophysics* and coordinated by ESO presented the most convincing evidence yet, confirming Betelgeuse B and refining its properties. The analysis, led by astronomer Miguel Montargès, estimates the companion’s mass to be roughly solar and suggests it orbits extremely close to Betelgeuse’s expanded surface. This tighter orbital configuration further supports the long‑term six‑year brightness modulation and adds a new dimension to the study of massive binary supergiant systems.

## Timeline

### 2026-08-02: Betelgeuse B Companion Star Confirmed by ESO Observations

ESO’s VLT observations reveal a hidden companion, Betelgeuse B, orbiting the red supergiant Betelgeuse in Orion, likely accounting for its long‑term brightness cycles.

2 sources. https://clstr.news/cluster/betelgeuse-b-companion-star-confirmed-by-eso-observations

### 2026-07-31: Astronomers Confirm Betelgeuse Has a Massive Companion Star

Astronomers led by Miguel Montargès used ESO’s VLT to image Betelgeuse’s companion, Betelgeuse B, finding it 2‑3 × solar mass and confirming a long‑sought binary star.

2 sources. https://clstr.news/cluster/astronomers-confirm-betelgeuse-has-a-massive-companion-star

### 2026-07-28: Betelgeuse’s long‑sought companion finally imaged by ESO’s VLT

ESO’s VLT has directly imaged Betelgeuse’s faint companion, Betelgeuse B, revealing it to be 2‑3 × solar mass and confirming a binary system that explains the star’s long‑term brightness changes.

21 sources. https://clstr.news/cluster/betelgeuse-found-to-have-massive-companion-star

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Cite as: Betelgeuse companion discovery. CLSTR, https://clstr.news/situations/betelgeuse-companion-discovery