New Open Cluster candidates Found in Galactic Disk Using Gaia DR2/EDR3 Data

TL;DR

This paper reports 541 new open cluster candidates in the Galactic disk identified using Gaia EDR3 data, expanding the known sample and demonstrating the potential for future discoveries with Gaia.

Contribution

The study introduces a new set of open cluster candidates identified with Gaia EDR3, utilizing pyUPMASK for membership probabilities and isochrone fitting for parameter estimation, revealing many previously unknown clusters.

Findings

541 new open cluster candidates identified

Most candidates have small proper motion dispersions

Metallicity gradient consistent with literature

Abstract

We report 541 new open cluster candidates in Gaia EDR3 through revisiting the cluster results from an earlier analysis of the Gaia DR2, which revealed nearly a thousand open cluster candidates in the solar neighborhood (mostly d < 3 kpc) resideing at Galactic latitudes |b| < 20 degrees. A subsequent comparison with lists of known clusters shows a large increases of the cluster samples within 2 kpc from the Sun. We assign membership probabilities to the stars through the open source pyUPMASK algorithm, and also estimate the physical parameters through isochrone fitting for each candidate. Most of the new candidates show small total proper motion dispersions and clear features in the color-magnitude diagrams. Besides, the metallicity gradient of the new candidates is consistent with those found in the literature. The cluster parameters and member stars are available at CDS via anonymous ftp to cdsarc.u-strasbg.fr(130.79.128.5) or via https://cdsarc.unistra.fr/viz-bin/cat/J/ApJS. The discovery of these new objects shows that the open cluster samples in Gaia data is still not complete, and more discoveries are expected in the future researches.