Context. Open clusters are ideal test particles for studying the
chemical evolution of the Galactic disc. However, the number and
accuracy of existing high-resolution abundance determinations, not only
of [Fe/H], but also of other key elements, remains largely insufficient.
Aims: We attempt to increase the number of Galactic open clusters
that have high quality abundance determinations, and to gather all the
literature determinations published so far. Methods: Using
high-resolution (R ~ 30 000), high-quality (S/N ≥ 60 per pixel), we
obtained spectra for twelve stars in four open clusters with the fibre
spectrograph FOCES, at the 2.2 Calar Alto Telescope in Spain. We employ
a classical equivalent-width analysis to obtain accurate abundances of
sixteen elements: Al, Ba, Ca, Co, Cr, Fe, La, Mg, Na, Nd, Ni, Sc, Si,
Ti, V, and Y. We derived oxygen abundances by means of spectral
synthesis of the 6300 Å forbidden line. Results: We provide
the first determination of abundance ratios other than Fe for NGC 752
giants, and ratios in agreement with the literature for the Hyades,
Praesepe, and Be 32. We use a compilation of literature data to study
Galactic trends of [Fe/H] and [α/Fe] with Galactocentric radius,
age, and height above the Galactic plane. We find no significant trends,
but some indication for a flattening of [Fe/H] at large Rgc,
and for younger ages in the inner disc. We also detect a possible
decrease in [Fe/H] with |z| in the outer disc, and a weak increase in
[α/Fe] with Rgc.
Based on observations collected with the fiber spectrograph FOCES at the
2.2 m Calar Alto Telescope. Also based on data from 2MASS survey and the
WEBDA, VALD, NIST, and GEISA online database.Table 12 is available in
electronic form at
http://www.aanda.orgFull Table 5 is only
available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr
(130.79.128.5) or via
http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/535/A30