Discovery of extended structure around open cluster COIN-Gaia 13 based on Gaia EDR3

TL;DR

This study uses Gaia EDR3 data and a membership algorithm to identify 478 members of the open cluster COIN-Gaia 13, revealing an extended structure likely caused by Galactic differential rotation and suggesting ongoing dynamical dissolution.

Contribution

It is the first detailed analysis of COIN-Gaia 13's extended structure using Gaia EDR3 data and pyUPMASK, providing new insights into its spatial distribution and dynamical state.

Findings

Identified 478 candidate members of COIN-Gaia 13.

Discovered an elongated extended structure about 270 pc long.

Suggests the cluster is undergoing dynamical dissolution due to Galactic differential rotation.

Abstract

COIN-Gaia 13 is a newly discovered open cluster revealed by Gaia DR2 data. It is a nearby open cluster with a distance of about 513 pc. Combined with the five-dimensional astrometric data of Gaia EDR3 with higher accuracy, we use the membership assignment algorithm (pyUPMASK) to determine the membership of COIN-Gaia 13 in a large extended spatial region. The cluster has found 478 candidate members. After obtaining reliable cluster members, we further study its basic properties and spatial distribution. Our results show that there is an obvious extended structure of the cluster in the X-Y plane. This elongated structure is distributed along the spiral arm, and the whole length is about 270 pc. The cluster age is 250 Myr, the total mass is about 439 M$_\odot$, and the tidal radius of the cluster is about 11 pc. Since more than half of the member stars (352 stars) are located outside twice the tidal radius, it is suspected that this cluster is undergoing the dynamic dissolution process. Furthermore, the spatial distribution and kinematic analysis indicate that the extended structure in COIN-Gaia 13 is more likely to be caused by the differential rotation of the Galaxy.