New Images Confirm Betelgeuse Has a Stellar Companion Named Siwarha
Astronomers have uncovered compelling evidence suggesting that Betelgeuse, a prominent star in the Orion constellation, is accompanied by a dim companion, which was detected at its furthest point in December 2024. The research, published in Astronomy and Astrophysics on July 28, could shed light on the evolutionary path of Betelgeuse. Co-author Miguel Montargès remarked, "We have shown that Betelgeuse is not single." Located approximately 550 light-years from Earth, Betelgeuse is a red supergiant with a mass between 16.5 and 19 times that of the sun. In 2025, another team captured a faint image of a potential companion, suggested to be called Siwarha, which is estimated to have a mass of 2.6 to 3.1 times the sun's and an orbital period of about six years. Further observations are planned for 2027.
Key facts
- New images provide best evidence yet that Betelgeuse has a stellar companion.
- Sighting occurred in December 2024 when companion was at farthest point from Betelgeuse.
- Findings published in Astronomy and Astrophysics on July 28.
- Companion named Siwarha, meaning 'her bracelet' in Arabic.
- Betelgeuse is a red supergiant about 16.5 to 19 times the sun's mass and 100,000 times as bright.
- Located roughly 550 light-years from Earth in constellation Orion.
- Companion is 2.6 to 3.1 times as massive as the sun, more than expected.
- Orbital period estimated at about six years.
- Confirmation expected in 2027 when companion appears on other side of star.
- Discovery may affect predictions of Betelgeuse's supernova timing.
Entities
Artists
- Miguel Montargès
- Andrea Dupree
- Sarah Blunt
Institutions
- Paris Observatory
- University of Colorado Boulder
- Harvard-Smithsonian Center for Astrophysics
- Very Large Telescope
- Astronomy and Astrophysics
Locations
- Chile
- Orion
- Earth