Dynamics of the atmosphere of Red SuperGiants: a view from spectropolarimetry and solar physics

by Dr Arturo López Ariste (CNRS+UPS/IRAP)

Wednesday 18 Mar 2026, 13:30 → 14:30 Europe/Stockholm

FC61 (AlbaNova Main Building)

Unexpectedly, linear polarization was found in the spectra of Betelgeuse a few years ago, and then in many other red supergiants. The interpretation of those signals in terms of brightness distributions led to images of the photosphere of these stars and from this to a change in the manner they were studied: from global, point-like objects to resolved and detailed stars which, like the Sun, are examined feature by feature. Convective structures and big plumes of overshooting plasma appeared, and measurements of velocities of the nascent wind were done. I will tour all these results and discuss the Great Dimming event that cloaked Betelgeuse in dust for a few months at the end of 2019.