APOGEE parameters through 83 open clusters

Existing measurements in a handful of open clusters suggest homogeneity in several elements at the 0.03dex level. Here we present (I) a new cluster member catalog based only on APOGEE radial velocities and Gaia-DR2 proper motions, (II) improved abundance uncertainties for APOGEE cluster members, and (III) the dependence of cluster homogeneity on Galactic and cluster properties, using abundances of eight elements from the APOGEE survey for 10 high-quality clusters.

We find that cluster homogeneity is uncorrelated with Galactocentric distance, |Z|, age, and metallicity. However, velocity dispersion, which is a proxy for cluster mass, is positively correlated with intrinsic scatter at relatively high levels of significance for [Ca/Fe] and [Mg/Fe]. We also see a possible positive correlation at a low level of significance for [Ni/Fe], [Si/Fe], [Al/Fe], and [Fe/H], while [Cr/Fe] and [Mn/Fe] are uncorrelated.