Photometric studies of open star clusters Haffner 11 and Czernik 31

•The physical parameters of the clusrers under study are derived.•The CCD photometric data for Czernik 31 have been collected for the first time.•These star clusters are very useful to study the structure and evolution in third Galactic quadrants. 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 and 3′.0 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±0.05mag and 0.48±0.05mag for the cluster Haffner 11 and Czernik 31 respectively. Using 2MASS JHKs and optical data, we determined E(J-K)=0.27±0.06mag and E(V-K)=1.37±0.06 for Haffner 11 and E(J-K)=0.26±0.08mag 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±0.5Kpc for Haffner 11 and 3.2±0.3Kpc 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±40Myr for Czernik 31 using the stellar isochrones of metallicity Z=0.019.