We present results on the age and metallicity estimates of the astonishingly unstudied Small Magellanic Cloud (SMC) cluster (ESO 51-SC09), from CCD BVI photometry obtained at the ESO NTT with the EMMI attached. ESO 51-SC09 turns out to be a relatively small cluster (FWHM=10+/-1pc) located ~4{deg} northward from the galaxy center. We report for the first time a mean cluster age of 7.0+/-1.3Gyr and a mean cluster metallicity of [Fe/H]=-1.00+/-0.15 dex, concluding that ESO 51-SC09 belongs to the group of the oldest SMC clusters. We found that the cluster is projected onto an older (age~10-13Gyr) and more metal-poor ([Fe/H]=-1.3+/-0.2 dex) dominant field stellar population, so that the cluster could have reached its current location because of its orbital motion.

Cone search capability for table J/ApJ/756/L32/table1 (BVI data of stars in the field of ESO 51-SC09)