A NEW DETERMINATION OF THE HUBBLE PARAMETER USING GALAXY LINEAR DIAMETERS

Measurements of the linear diameters of 12 nearby spiral galaxies, wit h Hubble types similar to that of the Milky Way and distances determin ed from primary indicators, suggest that the Milky Way and M31 are in the middle of the range of sizes for such galaxies, By comparing the m easured linear diameters of these nearby systems with the inferred dia meters of a sample of more than 1300 spirals with known redshifts, we conclude that the most likely value of the Hubble Parameter lies in th e range 50-55 km s(-1) Mpc(-1). By considering the distribution of the order statistics of the nearby sample, we conclude that values of H-0 > 80 km s(-1) Mpc(-1) are excluded at the 1 per cent level, based lar gely on the presence of two galaxies with linear diameters of D(25)sim ilar or equal to S 60 kpc in the nearby sample-provided that these nea rby spirals are a fair sample from the global distribution of linear d iameters deduced from the more distant sample. (C) 1997 American Astro nomical Society. [S0004-6256(97)00112-X].