Astrometric star-cluster membership probability: application to the case
  of M 37 with Gaia EDR3
  In this work, starting from the well-accepted relations in literature, we
introduce a new formalism to compute the astrometric membership probabilities
for sources in star clusters, and we provide an application to the case of the
open cluster M 37. The novelty of our approach is a refined -- and
magnitude-dependent -- modelling of the parallax distribution of the field
stars. We employ the here-derived list of members to estimate the cluster's
mean systemic astrometric parameters, which are based on the most recent Gaia's
catalog (EDR3).
