The Intrinsic I-Band Magnitude Dispersion of the Galactic Bulge Red
  Clump
  We measure the intrinsic magnitude dispersion of the Galactic bulge red clump
(RC) using two different methods and arrive at an estimate of \sigma_{I} ~ 0.17
mag. We first estimate the width of the RC by analyzing in detail a sample of
RC measurements toward double RC sightlines, which are toward regions of the
bulge that are geometrically thin. We obtain \sigma_{I} ~ 0.17 mag. We then
estimate the value by comparing the luminosity function for bulge RC and red
giant (RG) stars in V to that in I for a sightline near the plane, and we
obtain a value of \sigma_{I} ~ 0.14-0.17 mag. This result has structural and
evolutionary repercussions. It constrains model estimates of the bar's
orientation angle derived from RC studies as well as the inferred
characteristic length of the bar for a given characteristic height. Moreover,
the value is too large to account for using the predicted evolutionary effects
of the known metallicity distribution, implying the presence of other
population effects.
