BVI Photometry and the Red Giant Branch Luminosity Function of M15
  We present new $BVI$ photometry containing 40,000 stars of the Galactic
globular cluster M15 (NGC 7078) covering a $25 \times 25$ arcminute area
centered on the cluster with a magnitude range from the tip of the Red Giant
Branch to three magnitudes below the main sequence turn-off. Using
$\alpha$-enhanced Dartmouth Stellar Evolution Program models, we find an age of
$13.0 \ \pm \ 1.0$ Gyr and distance modulus of $(m-M)_V = 15.4 \pm 0.1$ through
isochrone fitting. Unlike previous works, we find good agreement between the
observed completeness-corrected stellar luminosity function and models.
