Photometric and kinematical analysis of Koposov 12 and Koposov 43 open clusters

TL;DR

This study combines photometric and kinematic data from Gaia DR2 and PPMXL to identify members and determine fundamental parameters like age, distance, and mass for the poorly studied open clusters Koposov 12 and Koposov 43.

Contribution

It provides the first detailed astrometric and photometric analysis of these clusters, estimating their ages, distances, masses, and kinematic properties using cross-matched Gaia and PPMXL data.

Findings

Koposov 12 age: 1 billion years, distance: 1850 pc.

Koposov 43 age: 3.16 billion years, distance: 2500 pc.

Cluster masses are approximately 360 solar masses.

Abstract

We present a photometric and kinematical analysis of two and poorly studied open clusters; Koposov 12 (FSR 802) and Koposov 43 (FSR 848) by using cross-matched data from PPMXL and Gaia DR2 catalog. We use astrometric parameters to identify 285 and 310 cluster members for Koposov 12 and Koposov 43, respectively. Using the extracted member candidates and isochrone fitting to near-infrared (J, H, Ks) and Gaia DR2 bands (G, GBP, GRP), and Color Magnitude Diagrams (CMDs), we have estimated ages: log (age/yr) = 9.00 +/- 0.20 and 9.50 +/- 0.20, and distances d = 1850 +/- 43 pc and 2500 +/- 50 pc for Koposov 12 and Koposov 43, respectively, assuming Solar metallicity (Z=0.019). The estimated masses of the cluster derived using initial mass function and synthetic CMD are 364 +/- 19 M_sun and 352 +/- 19 M_sun. We have also computed their velocity ellipsoid parameters based on (3x3) matrix elements (mu_ij).