The Age and Metallicity Dependence of the Near-Infrared Magnitudes of
  Red Clump Stars
  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
$M_{K_{S}}$, 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 $0.528 \pm 0.015$ and $0.047 \pm 0.011$, 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.
