Seminars

"The Zoo of Emission-Line B-Type Stars. Challenges in Determining the Fundamental Parameters"

Lydia Cidale (Facultad de Ciencias Astronómicas y Geofísica University of La Plata, Argentina)

B-type stars encompass distinct stellar groups with different evolutionary characteristics, including pre-main-sequence stars, main-sequence stars, blue supergiants, and post-AGB stars. Some B-type stars, even during the main-sequence stage, exhibit emission lines in their spectra, most notably Hα. Other B-type stars in transition phases show additional characteristics, such as forbidden emission lines and large infrared excesses, associated with the presence of molecules and dust in ring-like circumstellar structures. These stars are often embedded in their circumstellar material, making it extremely difficult to determine their fundamental parameters and establish their evolutionary status. During this seminar, I present the classification of the B-type stars and discuss various techniques for determining their stellar parameters, characterizing their IR properties, and identifying their evolutionary stages. Special emphasis is placed on the BCD spectrophotometric classification system and its applications to different types of stars.

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TBA (NCAC, Warsaw)