  The connection between age, rotation and chemical abundance of magnetic Ap
stars is poorly understood. Using open clusters, we are able to study samples
of stars that are both co-eval and co-environmental. By determining rotation
and chemical abundance for Ap star members of clusters with various ages, the
variations of these properties as a function of age and environment can be
derived. All four probable Ap star members of the open cluster NGC 6475, as
well as one normal late B star, were studied using detailed spectrum synthesis
of high resolution UVES-POP spectra. Probable cluster membership was confirmed
for all five stars, however chemical abundance anomalies only appear to be
present in spectra of three. Projected rotational velocity and chemical
abundances for 21 elements ranging from C to Eu are presented for the 5 stars.
In the three peculiar stars we find overabundances of Si, Cr, Mn, Fe and rare
earths such as Nd, characteristic of Ap stars. The set of chemically peculiar
stars show fairly homogeneous abundance tables, however notable differences
exist for a few elements. There also exist appreciable differences in the v sin
i and main sequence evolutionary stage of the chemically peculiar stars. This
may hint at the underlying processes giving rise to the observed abundance
anomalies. With this first detailed study of chemical abundances of a complete
sample of magnetic Ap/Bp stars in an open cluster, we have initiated an
exploration of the environmental and evolutionary influence on chemical
peculiarity.
