Photometric studies of open star clusters Haffner 11 and Czernik 31

TL;DR

This study conducts photometric analysis of open clusters Haffner 11 and Czernik 31, determining their physical parameters such as size, reddening, distance, and age using optical and infrared data.

Contribution

It provides new detailed photometric measurements and parameter estimates for these two open clusters, including their reddening, distance, and age, using combined optical and infrared observations.

Findings

Haffner 11 has a radius of 3.5 arcmin and is approximately 800 Myr old.

Czernik 31 has a radius of 3.0 arcmin and is approximately 160 Myr old.

Both clusters exhibit normal interstellar extinction law.

Abstract

We present the broad band UBVI CCD photometric investigations in the region of the two open clusters Haffner 11 and Czernik 31. The radii of the clusters are determined as 3.5 arcmin and 3.0 arcmin for Haffner 11 and Czernik 31 respectively. Using two colour (U-B) versus (B-V) diagram we determine the reddening E(B-V) = 0.50+/-0.05 mag and 0.48+/-0.05 mag for the cluster Haffner 11 and Czernik 31 respectively. Using 2MASS JHKs and optical data, we determined E(J-K) = 0.27+/-0.06 mag and E(V-K) = 1.37+/-0.06 for Haffner 11 and E(J-K) = 0.26+/-0.08 mag and E(V-K) = 1.32+/-0.08 mag for Czernik 31. Our analysis indicate normal interstellar extinction law in the direction of both the clusters. Distance of the clusters is determined as 5.8+/-0.5 Kpc for Haffner 11 and 3.2+/-0.3 Kpc for Czernik 31 by comparing the ZAMS with the CM diagram of the clusters. The age of the cluster has been estimated as 800+/-100 Myr for Haffner 11 and 160+/-40 Myr for Czernik 31 using the stellar isochrones of metallicity Z = 0.019.