High-resolution spectroscopic observations of the metal-poor, chemically peculiar, and high velocity Fehrenbach & Duflot star

Aims. We determine the atmospheric parameters and abundance pattern of the chemically peculiar metal-poor Fehrenbach & Duflot (Feh-Duf) star to more clearly understand its evolutionary state and the nature of the s-element enhancement in this star. Methods. Its atmospheric parameters and chemical abundances were determined using high resolution optical spectroscopy and employing the local-thermodynamic-equilibrium model atmospheres of Kurucz and spectral analysis code MOOG. Results. The derived abundances show that the Feh-Duf star is a low-metallicity ([Fe/H] = -1.93) star with high carbon and heavy s-element abundances, while the abundance of the light s-process element yttrium is low ([Y/Fe] = -0.07). The oxygen abundance is lower than for Galactic halo stars of similar metallicity. We conclude that the Feh-Duf star could be a CH star with C/O = 1.3. Another possibility is that the Feh-Duf star could be an early-AGB star. The Fehrenbach & Duflot star is also a lead star with [Pb/Ce] = +0.69. In addition, it displays an extreme retrograde motion (V-GRF = -259 km s(-1)), which in combination with its underabundance of alpha-elements suggests that this star may have been captured by the Milky Way galaxy.