Supernova distance measurements suggest an older, larger Universe.

Abstract

Three determinations of the Hubble constant from supernova observations are reviewed and compared to existing data on the age and size of the universe. Type-Ia supernovae are used as standard candles in all of the calculations, and the observations were made with the Hubble Space Telescope Wide-field and Planetary Camera. Hubble diagrams for the three sets of observations are described with attention given to the fact that Hubble constants of 50-60 km/sec-Mpc are determined in the datasets of Sandage et al. (1992), Branch (1992), and Schmidt et al. (1992). It is argued that the low Hubble constant values indicate either that higher values set forth in the 1980s are incorrect or that standard type-Ia supernovae are not adequate for use as standard candles.