The Status of the Distance Scale

Abstract

AbstractCepheids are the pillar of the extragalactic distance scale, but their reach in distance is not sufficient to calibrateH0Yet HST has provided Cepheid distances to eight galaxies which have produced SNe la. The latter are used as nearly perfect standard candles to carry the distance scale to 30 000 km s−1, givingH0= 58 ± 5. This determination finds support in other methods, but its range in distance and its weight is unparalleled.