A New Absolute Magnitude Calibration for Red Clump Stars
  We present an M_V absolute magnitude calibration including the B-V colour and
[Fe/H] metallicity for the red clump stars in the globular and open clusters
with a wide range of metallicities: M_V =
0.627(0.104)(B-V)o+0.046(0.043)[Fe/H]+0.262(0.111). The calibration equation is
valid in the ranges 0.42<(B-V)o<1.20 mag, -1.55<[Fe/H]<+0.40 dex and
0.43<M_V<1.03 mag. We found that the consistencies in the comparisons of the
distances estimated from the calibration equation in this study both with the
distances obtained from trigonometric parallaxes and spectrophotometric
analysis demonstrate that reliable precise absolute magnitudes for the clump
giants can be estimated from the calibration formula.
