Discovery of a new open cluster as a companion to Czernik 38 cluster and its associated complex tide, using Gaia DR3

TL;DR

Using Gaia DR3 data, the study discovers a new open cluster, Nasser 1, as a companion to Czernik 38, revealing insights into their shared origin and tidal interactions in the Carina-Sagittarius spiral arm.

Contribution

This paper reports the discovery and detailed characterization of Nasser 1 as a new open cluster and its association with Czernik 38, highlighting their potential common origin and tidal disruption.

Findings

Nasser 1 is confirmed as a genuine open cluster with specific age and distance.

Nasser 1 and Czernik 38 share similar physical parameters, indicating a binary system.

Both clusters show elongations due to differential rotation tides and spiral arm perturbations.

Abstract

We utilize Gaia DR3 data to report the discovery of a new star cluster, Nasser 1, located 32 arcmin from Czernik 38 at coordinates $\alpha= 282.11 \pm 0.05$ and $\delta= 4.56 \pm 0.05$. Using a variable membership probability threshold technique with pyUPMASK, we confirm Nasser 1 as a genuine open cluster. It exhibits a distinct King profile and a well-defined CMD with an age of $125.0 \pm 12.30$ Myr, a distance modulus of $12.87 \pm 0.21$ mag, and a color excess of $2.42 \pm 0.09$. Nasser 1 shares consistent physical parameters (age, distance, kinematics, and reddening) with Czernik 38, suggesting they constitute a young primordial binary system in the Carina-Sagittarius spiral arm. Both clusters display elongations indicative of differential rotation tides; Nasser 1 is additionally perturbed by the spiral arm's gravitational field. Gaussian mass function analysis suggests the two were formerly a single cluster, violently torn apart by differential rotation.