Planetary nebulae as standard candles. V. The distance to the Virgo Cluster

We identify and measure the [O III] λ5007 fluxes of 486 planetary nebula candidates in six early-type galaxies (NGC 4374, 4382, 4406, 4472, 4486, and 4649) in the core of the Virgo Cluster. Following the procedures and calibrations outlined in previous papers in this series, we compare the observed planetary nebula lumin osity functions to an empirical model based on the planetary nebulae in M31 and derive distances to the galaxies of 15.7, 14.4, 15.7, 13.9, 14.5, and 14.2 Mpc. These distances exhibit superb agreement with a dispersion of only 0.8 Mpc and suggest that the cluster depth is less than 2 Mpc. Most importantly, the distances are totally uncorrelated with parent galaxy metallicity, color, UV flux, or Hubble type. After accounting for all contributions to the uncertainty, we derive a mean distance of 14.7 ± 1.0 Mpc to the core of the Virgo Cluster. This distance implies that the Hubble constant falls in the range of 81 ± 6 to 94 ± 6 km s^-1 Mpc^-1, depending on the adopted Virgo velocity and infall model.