Hubble Reveals Betelgeuse’s Hidden Companion Star in Stunning Discovery

Astronomers have made a significant breakthrough in understanding the peculiar behavior of the red supergiant star, Betelgeuse. Utilizing nearly eight years of observations from NASA’s Hubble Space Telescope and ground-based observatories, researchers have confirmed the existence of a previously hidden companion star, named Siwarha. This companion is causing disruptions in Betelgeuse’s atmosphere, leaving behind a visible trail of gas.

The findings were presented during a news conference at the 247th meeting of the American Astronomical Society in Phoenix, with the results accepted for publication in The Astrophysical Journal. This discovery not only sheds light on Betelgeuse’s unusual brightness variations but also enhances our understanding of the life cycles of massive stars.

Revealing the Stellar Wake

The research team from the Center for Astrophysics | Harvard & Smithsonian detected changes in Betelgeuse’s brightness over nearly eight years, revealing the impact of a companion star that had long been suspected but not confirmed. By analyzing the light patterns, they found that as Siwarha moves through Betelgeuse’s outer layers, it disrupts the surrounding gas, creating a dense wake.

This discovery addresses a long-standing question about the star’s variability. Previously, astronomers had proposed various theories to explain Betelgeuse’s behavior, including convection cells and magnetic activity, but the confirmation of Siwarha as a companion star provides a clearer explanation for the star’s changes.

Understanding Betelgeuse’s Variability

Betelgeuse, located approximately 650 light-years from Earth in the constellation Orion, is one of the largest stars known, capable of containing more than 400 million Suns. Its proximity makes it a critical subject for studying the life cycles of large stars, including their material loss and eventual supernova explosions.

Astronomers have been monitoring Betelgeuse for decades, noting significant fluctuations in brightness. Interest peaked in 2020 when the star experienced an unexpected dimming event. The research revealed two distinct cycles in its variability: a short 400-day cycle linked to internal pulsations and a longer 2,100-day cycle. The identification of Siwarha provides the strongest evidence yet for the influence of a companion star on these cycles.

Andrea Dupree, an astronomer at the CfA and lead author of the study, described the phenomenon as akin to a boat moving through water, creating ripples. This is the first time direct evidence of a stellar wake has been observed, confirming that Betelgeuse has a hidden companion affecting its atmospheric behavior.

The discovery of Siwarha not only elucidates Betelgeuse’s complex behavior but also offers valuable insights into the evolutionary processes of other massive stars nearing the end of their life cycles.

Future observations are planned as Betelgeuse is currently obscuring its companion from view. The next window for study will open in 2027, when the companion star becomes visible again. This research could also help illuminate similar mysteries surrounding other giant and supergiant stars.

The Hubble Space Telescope, now operational for over 30 years, continues to play a pivotal role in deepening our understanding of the universe. Managed by NASA’s Goddard Space Flight Center in Maryland, in collaboration with the European Space Agency, Hubble remains a vital instrument in modern astronomy.

This latest discovery highlights the importance of long-term observational studies and reinforces Hubble’s legacy in contributing to groundbreaking astronomical research.