Cosmic Origins
6 January 2026
NASA Hubble Helps Detect ‘Wake’ of Betelgeuse’s Elusive Companion Star
Using new observations from NASA’s Hubble Space Telescope and ground-based observatories, astronomers tracked the influence of a recently discovered companion star, Siwarha, on the gas around Betelgeuse. The research, from scientists at the Center for Astrophysics | Harvard & Smithsonian (CfA), reveals a trail of dense gas swirling through Betelgeuse’s vast, extended atmosphere, shedding light on why the giant star’s brightness and atmosphere have changed in strange and unusual ways.
The results of the new study were presented Monday at a news conference at the 247th meeting of the American Astronomical Society in Phoenix and are accepted for publication in The Astrophysical Journal.
The team detected Siwarha’s wake by carefully tracking changes in the star’s light over nearly eight years. These changes show the effects of the previously unconfirmed companion as it plows through the outer atmosphere of Betelgeuse. This discovery resolves one of the biggest mysteries about the giant star, helping scientists to explain how it behaves and evolves while opening new doors to understanding other massive stars nearing the end of their lives.
American Astronomical Society
The 247th Meeting of the AAS
The 247th Meeting of the American Astronomical Society (joint with the Historical Astronomy Division) will be held 4-8 January 2026 in Phoenix, Arizona.
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