GLOBULAR CLUSTERS AND VIRGO CLUSTER DISTANCE MODULUS

Photometry presented by Hanes for the globular clusters associated with 20 bright galaxies in the Virgo cluster is used in an evaluation of a pure Population II distance modulus for the Virgo cluster of galaxies. The assumption of a normally distributed universal globular cluster luminosity function, calibrated in the Galaxy sample of globulars and based upon an absolute magnitude of MV = 0.6 mag for RR Lyrae stars in globular clusters, leads to Virgo cluster distance modulus estimates near (m-M)app =30.4 mag, with an uncertainty of ± 0.5 mag. Confirmation of a model-independent nature is presented. © 1977 Royal Astronomical Society. Provided by the NASA Astrophysics Data System.