Using new observations from NASA’s Hubble Space Telescope and ground-based observatories, astronomers have tracked the influence of a recently discovered companion star, Siwarha, on the gas around Betelgeuse. The research, by 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.