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Last name: LÈBRE
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Astronomy and Astrophysics, v. 400, p. 613-621, 2003. http://dx.doi.org/10.1051/0004-6361:20030076
Red supergiant stars are one of the latest stages in the evolution of massive stars. Their photospheric convection may play an important role in the launching mechanism of their mass loss; however, its characteristics and dynamics are still poorly constrained.By observing red supergiant stars with near infrared interferometry at different...
Aims.We study the links possibly existing between the lithium content of bright giant stars and their rotational velocity. Methods: .We performed a spectral analysis of 145 bright giant stars (luminosity class II) spanning the spectral range from F3 to K5. All these stars have homogeneous rotational velocity measurements available in the...
Astronomy and Astrophysics, 504, pp. 1011-1019 (2009)
International audience
In this work we present atmospheric parameters and Li abundances, obtained from a detailed spectroscopic analysis, for a large sample of stars with different evolutionary stages (turn-off, subgiant and giant stars) in the open cluster M67. The observations were carried out with high resolution (R ~ 47,000) and high S/N using the UVES+FLAMES at...
Aims.We report the serendipitous discovery of a lithium-rich subgiant star, S1242. This object is member of a large eccentricity spectroscopic binary system in the solar-age open cluster M 67. Methods.Using VLT/FLAMES-UVES observations and synthetic spectrum analysis, we derived for this star stellar parameters (temperature, gravity,...
Context. Betelgeuse is an M-type supergiant that presents a circularly polarized (Stokes V) signal in its line profiles, interpreted in terms of a surface magnetic field.Aims. The weak circular polarization signal has been monitored over 7.5 years in order to follow its evolution on different timescales, and eventually to determine its physical...