NGC 2112, 2477, 7789 and Col 261 members

This paper aims to evaluate the effectiveness of the Gaussian mixture model (GMM) in segregating likely cluster members of open clusters in high-noise environments. We use the GMM method to segregate likely cluster members of four low Galactic latitude open clusters: NGC 2112, NGC 2477, NGC 7789, and Collinder 261, based on the high-precision astrometric data of the Gaia Data Release 2 (Gaia-DR2).

The GMM method is used to calculate the membership probabilities of the stars in the field of each cluster; five astrometric parameters (positions, parallaxes, and proper motions) are taken into account. We quantitatively evaluate the goodness of the cluster-field segregation for each cluster, and find that the GMM method is effective for segregating likely cluster members of these clusters, even if these clusters suffer from heavy field star contamination.