Revisiting the mass of open clusters with \emph{Gaia} data

TL;DR

This study introduces a new method to accurately determine the masses of open clusters and their binary populations using Gaia data, enabling large-scale analysis of cluster mass functions and properties.

Contribution

The paper presents a novel method for estimating individual stellar masses, including binaries, and applies it to a large sample of Gaia-observed open clusters.

Findings

Validated the method with synthetic clusters

Applied to 773 clusters using Gaia eDR3 data

Found no significant mass loss or segregation with age

Abstract

The publication of the \emph{Gaia} catalogue and improvements in methods to determine memberships and fundamental parameters of open clusters has led to major advances in recent years. However, important parameters such as the masses of these objects, although being studied mostly in some isolated cases, have not been addressed in large homogeneous samples based on \emph{Gaia} data, taking into account details such as binary fractions. Consequently, relevant aspects such as the existence of mass segregation were not adequately studied. Within this context, in this work, we introduce a new method to determine individual stellar masses, including an estimation for the ones in binary systems. This method allows us to study the mass of open clusters, as well as the mass functions of the binary star populations. We validate the method and its efficiency and characterize uncertainties using a grid of synthetic clusters with predetermined parameters. We highlight the application of the method to the Pleiades cluster, showing that the results obtained agree with the current consensus in the literature as well as recent \emph{Gaia} data. We then applied the procedure to a sample of 773 open clusters with fundamental parameters determined using \emph{Gaia Early Data Release 3 (eDR3)} data, obtaining their masses. Subsequently, we investigated the relation between the masses and other fundamental parameters of the clusters. Among the results, we found no significant evidence that clusters in our sample lose and segregate mass with age.