A comprehensive photometric and kinematical characteristic of the newly discovered QCs clusters with Gaia EDR3

Abstract

This study reports the first comprehensive astrometric, photometric, and kinematical analysis of four newly discovered open clusters; namely QC1, QC2, QC3, and QC4, using astrometric and photometric data from the most recent Gaia EDR3 for $G <17$ mag. Utilizing the ASteCA code, we identified the most probable ($P \ge 50$%) star candidates and found the numbers of star members (N) to be 118 (QC1), 142 (QC2), 210 (QC3), and 110 (QC4). By fitting King’s density profile to the cluster’s RDPs, we found the internal structural parameters of each cluster such as the cluster radii that are in the range 7.00–11.00 arc-min. For each cluster, we constructed the CMD and by fitting them with suitable isochrones we found that the metallicity range is (0.0152–0.0199) which is in line with the Solar value, the logarithmic age (in yrs) range between 6.987 and 8.858. The distances derived from CMD are $1674\pm 41$, $1927\pm 44$, $1889\pm 43$, and $1611\pm 40$ (pc) for QC1, QC2, QC3, and QC4, respectively, and they are in good agreement up to 85% with the values obtained from the astrometric data. In addition, from the MLR of the clusters, we obtained a total mass, $M_C$ in Solar units, of 158, 177, 232, and 182 and an absolute magnitude $M_G$ (mag) of 4.33, 3.80, 4.25, and 4.10 for QC1, QC2, QC3, and QC4, respectively. The dynamical analysis and evolution parameters of the cluster members indicated that all the four clusters are dynamically relaxed; except QC1 which has an evolution parameter $\tau \sim 0.82$ that indicates a dynamical activity within the cluster. From the kinematical analysis of the cluster data, we computed the space velocity, the coordinates of the apex point (A, D) using the AD—diagram method, as well as the Solar elements ($S_{\odot }$, $l_{A}$, $b_{A}$, $\alpha _{A}$, $\delta _{A}$).