The distance of the Hercules supercluster from supernovae and SBC spirals, and the Hubble constant.

The distance modulus of the Hercules supercluster of galaxies is determined anew by two independent methods: (1) the maximum apparent luminosities of presumed Type I supernovae, >m_pg< = 17.0, give a mean corrected modulus μ₀ = 35.22±0.28; and (2) the mean apparent magnitudes and diameters of seven Sbc spirals of luminosity classes I to II, corrected for extinction, give a mean corrected modulus μ₀ = 35.27±0.15. This leads to a value of the Hubble ratio, >H^*< = 99±7 km s^-1Mpc^-1, which should be free of both Malmquist bias and the effect of local perturbations. The corresponding value of the Hubble constant, H₀, depends slightly on cosmological model and corrections.