M 104 planetary nebulae

We present the positions and monochromatic [O III] lambda 5007 magnitudes of 294 planetaries, and use the observed planetary nebula luminosity function (PNLF) to measure a distance of 8.9+/-0.6Mpc to the galaxy. The luminosity-specific PN number lambda 2.5 in the halo of M104 is approximately 21.7x10^-9^L_{sun}_, which for its color (B-V)=0.95, is comparable to the values in other galaxies.

We use the PNLF distance to M104 to compare its luminosity to the luminosities of the brightest galaxies in the Virgo Cluster, finding that if M104 were in the Virgo Cluster, it would be the third brightest galaxy. We combined the PNLF distance and the observed velocity corrected for Virgo infall to calculate a Hubble constant H_0_=91+/-8km/s/Mpc. We also used the PNLF distances to the NGC 1023 group, the Leo group, the Virgo Cluster, and the Fornax Cluster to derive Hubble constants corrected for Virgo infall.