The MiMO Catalog: Physical Parameters and Stellar Mass Functions of 1232 Open Clusters from Gaia DR3

Abstract We present a homogeneous catalog of 1232 open clusters with precisely determined ages, metallicities, distances, extinctions, and stellar mass function (MF) slopes, derived from Gaia DR3 data. The parameters are inferred using the Mixture Model for Open clusters (MiMO), a novel Bayesian framework for modeling clusters in the color–magnitude diagram. By explicitly accounting for field-star contamination as a model component, MiMO removes the conventional need for stringent membership preselection, allowing for a more complete inclusion of member stars, and thereby enhancing both precision and robustness. Our results broadly agree with existing catalogs but offer improved precision. For each cluster, we provide the best-fit age, metallicity, distance, extinction, and MF slope, along with their full likelihood chains and photometric membership probabilities for individual stars. We further identify an “MF Prime” subsample of 163 clusters with high-quality data, for which the MF estimates are considered most reliable. The catalog and an open-source implementation of MiMO are made publicly available to the community.