MISHENINA, T. V.; SOUBIRAN, C.; KOVTYUKH, V. V.; KATSOVA, M. M.; LIVSHITS, M. A.

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MISHENINA, T. V.
Astronomical observatory of Odessa National University [Odessa]

SOUBIRAN, C.
M2A 2012

KOVTYUKH, V. V.
Astronomical observatory of Odessa National University [Odessa]

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Ce document a été publié dans

Memorie della Societa Astronomica Italiana Supplementi. 2012, vol. 22, p. 121

Istituto Nazionale di Astrofisica Osservatorio Astronomico di Trieste

Résumé en anglais

Li abundances, atmospheric parameters and rotational velocities for 150 dwarfs have been determined from the high resolution, high signal to noise echelle spectra, obtained with the ELODIE spectrograph at the OHP (France). Among them, there are 101 stars with a determined level of activity, a large part of them being of the BY Dra type. The level of chromospheric and coronal activity of the targets has been evaluated through the logR'_HK index and X-ray flux. We examined the Li abundance behavior with T_eff, vsini and level of the activity. Some correlations between the Li abundances, level of the chromospheric activity and rotational velocities vsini are confirmed. The correlation between the Li abundances and index of the chromospheric activity logR'_HK was found, especially for dwarfs with 5700>T_eff> 5200 K. Those correlations mainly demonstrate that measurable values of the lithium content (higher than the upper limit) refer to the stars with large spot areas in their photospheres. Considering the wider set of stars with high activity levels one can affirm that such a conclusion is valid also for the cooler, earlier K dwarfs. Our results confirm that basic factors of formation of detectable Li abundance and high activity are determined principally by smaller age and fast axial rotation, respectively; and apparently by the depth of the convective zone.< Réduire

Mots clés en anglais

Stars: late type

Stars: fundamental parameters

Stars: abundances

Stars: rotation

Stars: activity

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Importé de hal

Unités de recherche

Laboratoire d'Astrophysique de Bordeaux (LAB) - UMR 5804