Measuring the Hubble Constant with the Hubble Space Telescope

Robert C., Jr. Kennicutt, Wendy L. Freedman, Jeremy R. Mould
1995 Astronomical Journal  
Ten years ago our team completed the Hubble Space Telescope Key Project on the extragalactic distance scale. Cepheids were detected in some 25 galaxies and used to calibrate four secondary distance indicators that reach out into the expansion field beyond the noise of galaxy peculiar velocities. The result was H 0 = 72 ± 8 km s −1 Mpc −1 and put an end to galaxy distances uncertain by a factor of two. This work has been awarded the Gruber Prize in Cosmology for 2009.
doi:10.1086/117621 fatcat:cpl4wyhxy5ezfe3q3oifpjt4ou