HUBBLE-SPACE-TELESCOPE OBSERVATIONS OF GLOBULAR-CLUSTERS IN M87 AND AN ESTIMATE OF H-0

Hubble Space Telescope observations of over 1000 globular clusters in the central region of M87 have been made using the Wide Field and Plan etary Camera 2. The limiting magnitude in V is 26 mag, more than 2 mag beyond the turnover of the luminosity function. The distribution is w ell fitted by a Gaussian profile with a mean of [m(V)(0)] = 23.72 +/- 0.06 mag and a width of 1.40 +/- 0.06 mag. Assuming a value of [M(V)(0 )] = -7.4 +/- 0.25 mag for the globular cluster luminosity function re sults in a distance modulus of (m - M) = 31.12 mag to the Virgo Cluste r. Using a value of Delta(Coma-Virgo)(m - M) = 3.71 +/- 0.10 mag and a dopting a velocity for the Coma Cluster of 7188 km s(-1) result in a v alue for the Hubble constant of H-0 = 78 +/- 11 km s(-1) Mpc(-1). The V - I color distribution is bimodal, with peaks at V - I = 0.95 mag an d 1.20 mag. The mean size of the clusters is R(eff) = 3 pc, with a sca tter of 1 pc.