Betelgeuse reveals a wake created by its companion Siwarha.

Hubble data show a wake in Betelgeuse's atmosphere produced by a previously suspected companion star named Siwarha. Siwarha is roughly 1.5 times the Sun's mass, orbits at about 4 astronomical units, and completes an orbit in roughly 5.7–6 years.

Recent Hubble observations identify a wake in Betelgeuse's upper atmosphere that is linked to a previously hidden companion star called Siwarha. Astronomers had proposed a companion in prior years but lacked direct evidence until these spectral and imaging data. Over about eight years, Hubble and ground observatories tracked repeating changes in the star's spectrum and a trail of dense gas that recurs on a roughly six-year timescale. Those patterns, together with a 2023 surface mass ejection that produced cooling dust, are now understood as effects related to the companion's orbit. Key observations: - Hubble Space Telescope data and spectral analysis show a wake or trail of dense gas associated with a companion star. - The companion, named Siwarha in 2025, is reported to be about 1.5 times the mass of the Sun and orbits at roughly 4 astronomical units. - Siwarha's orbital period is measured at about 5.7–6 Earth years, matching the roughly six-year recurrence of the wake. - A surface mass ejection in 2023 produced dust that cooled and contributed to a dimming event in Betelgeuse's light. - Betelgeuse and its companion lie about 650 light-years from Earth. - Astronomers note the next favorable opportunity to observe Siwarha as it moves out from behind Betelgeuse is expected in 2027. Summary: The detection of Siwarha's wake provides a coherent explanation for several observed brightness and atmospheric changes in Betelgeuse. Further observations are expected, with a planned viewing opportunity when Siwarha emerges from behind Betelgeuse in 2027.