Abstract

Invited Talk - Plenary

Wednesday, 09 September 2026, 09:30   (MW-1801 / virtual plenum)

A changing perspective on massive stars: Insights from detailed atmosphere modelling

Andreas Sander
ITAP, Christian-Albrechts-Universität zu Kiel

Hot, massive stars are astrophysical keystones which shape their environment via mechanical and radiative feedback and chemically enrich their cosmic neighbourhood since the first generation of (very) massive stars. However, turning this general textbook picture into quantitative prediction remains an ongoing challenge. Recent discoveries, such the surprisingly high metallicity and early nitrogen enrichment in high-redshift galaxies discovered by JWST, put current descriptions and modelling approaches into question, illustrating that the complex puzzle of massive stars and their interplay is everything but complete. To get a robust, quantitative understanding, decoding and predicting the light of hot massive stars marks an astrophysical key technique. In turn, the necessary complex stellar atmosphere models can also be used to get pioneering insights into the radiatively driven mass loss of hot, massive stars. In this talk, I will present a selection of recent research results obtained from detailed atmosphere modelling changing our view of the properties and evolution of massive stars. A prominent example will be the recent discovery of an unexpected direct transition in the Wolf-Rayet regime from WN to WO subtype, illustrating how the study of individual objects provides fundamental insights on missing ingredients in current population synthesis.