New evolutionary clues to understand the nature of massive starsRecording

by Abel de Burgos Sierra (Instituto de Astrofísica de Canarias)

Monday Sep 30, 2024, 10:30 AM → 12:00 PM Europe/Madrid

00.303.0 - Aula 13 (Facultad de Ciencias Físicas)

Massive stars play a crucial role in shaping the Universe, despite that, comparisons between observational data and theoretical models of massive stars have given rise to long-standing and new discrepancies that have questioned our understanding of these objects. One of the main uncertainties arises from the overdensity of B-type supergiants (BSGs) in the Hertzsprung-Russell diagram where models predict the termination of the main sequence (TAMS). Whether the location of the TAMS has to be redefined, or the overdensity is the result of overlapping populations following different evolutionary paths, is still uncertain.
In this seminar, I will present the main outcomes of my PhD thesis, which aims at improving this situation by carrying out a holistic empirical study of the physical, chemical, and pulsational properties of the largest spectroscopic sample of BSGs analyzed to date. For this, I combine high-resolution spectroscopic data with Gaia astrometry and TESS photometry of a sample of more than 700 Galactic BSGs. The results provide important clues about the nature of these objects and establish new solid constraints to the evolutionary models of massive stars, narrowing down existing discrepancies.

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