A Remarkable Star
Fresh radio observations of Betelgeuse from ALMA have exposed a strikingly uneven atmosphere around the star, including patches of intense heat that appear to have stayed put for seven years. Betelgeuse is among the closest massive stars to Earth and is nearing the end of its life. With a mass roughly 14 times that of the Sun and a radius beyond 650 solar radii, it would stretch all the way to Jupiter’s orbit if it sat where our Sun does.
High Temperatures and Churning Motion
The layers of the atmosphere examined in the study average around 2000 °C. In the latest images, two brilliant regions stand out, each several hundred degrees hotter than the surrounding gas. A side-by-side comparison with observations made seven years earlier shows these hot regions have barely changed in shape or location. The researchers suggest the long-term persistence of these convective cells could be linked to a possible stellar companion, Betelgeuse B.
This work was accepted for publication in Astronomy & Astrophysics, and a preprint is currently available on arXiv. The news report was published on August 25 at 21:07.
Studying Betelgeuse, one of the night sky's most familiar stars, is providing fresh insight into its evolution and the physical processes at work in its atmosphere. The behavior of its hot spots and uneven outer layers could shed new light on how stars behave in their final evolutionary phases, and it may open up further avenues for exploring stellar systems and their effects on their surroundings. Above all, this work is a reminder of how powerful modern instruments such as ALMA are in transforming what we know about the universe.