Observations reveal evidence of a potential stellar companion for the red supergiant Betelgeuse

Star system: Betelgeuse | Distance from the Sun: 723 light years

Betelgeuse, one of the most prominent red supergiant stars in the night sky, has long been a subject of intense scientific inquiry. Recent analysis has sought to verify the existence of a secondary star orbiting this massive primary. By examining the star’s long secondary period of variability, which suggested the presence of an orbiting body, researchers targeted the system to confirm if a companion star was indeed present in the vicinity of this stellar giant.

Using extreme adaptive optics, a technique that compensates for atmospheric blurring to provide sharp images, the Very Large Telescope’s SPHERE-ZIMPOL instrument captured direct imagery of the region. The team employed specialized image-processing methods, known as angular plus spectral differential imaging, to filter out the overwhelming glare of the primary star and isolate potential faint signals from a secondary source.

The search resulted in the detection of a candidate object, designated Betelgeuse B, on December 6, 2024. The detected object is located at a separation of 52.32 milliarcseconds from the primary star. If the two stars originated at the same time, this companion is estimated to be a young main-sequence star with a mass between 2.6 and 3.1 times that of the Sun. While these results provide strong evidence for the companion's existence, a second observation in the future is required to formally confirm that the two stars are gravitationally bound.

Key findings
- A candidate companion, Betelgeuse B, was detected at a separation of 52.32 milliarcseconds.
- The object was identified using high-contrast adaptive optics imaging and advanced data processing.
- Betelgeuse B is estimated to be a young main-sequence star between 2.6 and 3.1 solar masses.
- The detection validates the use of long secondary period variability as a tool for identifying companions around red supergiants.

Scientific study

VLT/SPHERE imaging of the candidate companion of Betelgeuse (external link)