Presentation #201.06 in the session Star Clusters and Associations — iPoster Session.
The recently re-discovered open cluster Stock 2, located roughly 375 pc away and about 450 Myr old, has the potential to be an exciting new testbed for our understanding of stellar evolution. We present results from a spectroscopic campaign to characterize stars near the cluster’s main-sequence turnoff, with the goal of identifying candidate chemically peculiar stars among the cluster’s A stars. Our data include our own échelle spectra for 66 cluster members obtained with ESPaDOnS on the 3.6-m Canada-France-Hawaii Telescope, Hawaii, and six stars observed with SOPHIE on the 1.93-m telescope at the Observatoire de Haute-Provence, France. We complemented these new observations with those of 32 high-mass cluster members by Alonso-Santiago et al. We derived the stellar parameters Teff, log g, ve sini, [X/H], ξt) for our sample using the Sliced Inverse Regression technique and then used iSpec with ATLAS9 model atmospheres and SPECTRUM radiative transfer code to derive 1D LTE individual abundances through spectral synthesis fitting. We used these abundance measurements to identify A stars with anomalous levels of scandium, calcium, and other metallic lines. Follow-up observations of these Am candidates with known ages will be required to understand the competition between atomic diffusion and other macroscopic processes in stellar interiors.