2019MNRAS.486.5600O

Red clump (RC) stars are widely used as an excellent standard candle. To make them even better, it is important to know the dependence of their absolute magnitudes on age and metallicity. We observed star clusters in the Large Magellanic Cloud to fill age and metallicity parameter space, which previous work has not observationally studied. We obtained the empirical relations of the age and metallicity dependence of absolute magnitudes M_J, M_H, and M_KS_, and colours J - H, J - K_S, and H - K_S of RC stars, although the coefficients have large errors. Mean near-infrared magnitudes of the RC stars in the clusters show relatively strong dependence on age for young RC stars. The J - K_S and H - K_S colours show the nearly constant values of 0.528 ± 0.015 and 0.047 ± 0.011, respectively, at least within the ages of 1.1-3.2 Gyr and [Fe/H] of -0.90 to -0.40 dex. We also confirmed that the population effects of observational data are in good agreement with the model prediction.