A STUDY OF THE NGC 1193 AND NGC 1798 OPEN CLUSTERS USING CCD UBV PHOTOMETRIC AND GAIA EDR3 DATA

Abstract

We present photometric, astrometric, and kinematic studies of the old open star clusters NGC 1193 and NGC 1798. Both of the clusters are investigated by combining data sets from Gaia Early Data Release 3 (EDR3) and CCD UBV observational data. E(B − V ) color excesses are derived for NGC 1193 as 0.150 ± 0.037 and for NGC 1798 as 0.505 ± 0.100 mag through the use of two-color diagrams. Photometric metallicities are also determined from two-color diagrams with the results of [Fe/H]=−0.30 ± 0.06 dex for NGC 1193 and [Fe/H]=−0.20 ± 0.07 dex for NGC 1798. The isochrone fitting distance and age of NGC 1193 are 5562 ± 381 pc and 4.6±1 Gyr, respectively. For NGC 1798, these parameters are 4451±728 pc and 1.3±0.2 Gyr. Kinematic and dynamic orbital calculations indicate that NGC 1193 and NGC 1798 belong to the thick-disk and thin-disk populations, respectively.