... stars

Based on observations collected with the CORALIE spectrograph attached to the Euler Telescope of the Geneva Observatory situated at La Silla (Chile).

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... analysis

Figures 2, 3, 6, 8-10, 13-18, 21-24 are only available in electronic form at http://www.edpsciences.org

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...

The colours are given in the electronic version only.

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