Aims. Analyses of Galactic late O dwarfs (O8-O9.5V stars) raised the "weak wind problem": spectroscopic mass loss rates (˙ M) are up to two orders of magnitude lower than the theoretical values. We investigated the stellar and wind properties of Galactic late O giants (O8-O9.5III stars). These stars have luminosities log(L /L) ≈ 5.2, this is...
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August 1, 2019 (v1)Journal articleUploaded on: December 4, 2022
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2021 (v1)Journal article
Context. The evolution of massive stars depends on several physical processes and parameters. Metallicity and rotation are among the most important, but their quantitative effects are not well understood.Aims. To complement our earlier study on main-sequence stars, we study the evolutionary and physical properties of evolved O stars in the...
Uploaded on: December 4, 2022 -
2008 (v1)Journal article
International audience
Uploaded on: December 3, 2022 -
June 23, 2011 (v1)Conference paper
Gaia will observe up to a billion stellar sources. Automated algorithms are under development to derive the atmospheric parameters of all observed spectra, from low resolution optical spectra alone or in synergy with high resolution spectra in the near-IR Ca II triplet region. To do so, a large database of state-of-the-art stellar libraries has...
Uploaded on: December 3, 2022