Unveiling the Evolutionary State of Three B Supergiant Stars: PU Gem, ϵ CMa, and η CMa

0576370 - ASÚ 2024 RIV CH eng J - Journal Article
Sánchez Arias, Julieta Paz - Németh, Péter - de Almeida, E.S.G. - Ruiz Diaz, M. A. - Kraus, Michaela - Haucke, M.
Unveiling the Evolutionary State of Three B Supergiant Stars: PU Gem, ϵ CMa, and η CMa.
Galaxies. Roč. 11, č. 5 (2023), č. článku 93. E-ISSN 2075-4434
R&D Projects: GA ČR(CZ) GA20-00150S; GA ČR(CZ) GA22-34467S
EU Projects: European Commission(XE) 823734 - POEMS
Institutional support: RVO:67985815
Keywords : massive stars * supergiants * winds
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 2.5, year: 2022
Method of publishing: Open access

We aim to combine asteroseismology, spectroscopy, and evolutionary models to establish a comprehensive picture of the evolution of Galactic blue supergiant stars (BSG). To start such an investigation, we selected three BSG candidates for our analysis: HD 42087 (PU Gem), HD 52089 (ϵ CMa), and HD 58350 (η CMa). For our analysis, we utilized the 2-min cadence TESS data to study the photometric variability, and we obtained new spectroscopic observations at the CASLEO observatory. We used non-LTE radiative transfer models calculated with CMFGEN to derive their stellar and wind parameters. For the fitting procedure, we included CMFGEN models in the iterative spectral analysis pipeline XTgrid to determine their CNO abundances. The spectral modeling was limited to changing only the effective temperature, surface gravity, CNO abundances, and mass-loss rates. Finally, we compared the derived metal abundances with prediction from Geneva stellar evolution models.
Permanent Link: https://hdl.handle.net/11104/0345940