Number 88 (Story #2), July 13, 1992 by Phillip F. Schewe and Ben Stein A NEW VALUE FOR THE HUBBLE CONSTANT has been obtained by calibrating the intrinsic brightness of type-IA supernovas, which can be observed in distant galaxies, against the intrinsic brightness of cepheid variable stars, which can be observed only in relatively nearby galaxies. Allan Sandage of the Carnegie Institution and his colleagues have used the Hubble Space Telescope to observe 27 cepheids in galaxy IC4182; the reliable relation between the cepheids' variability rate and intrinsic brightness gives a value of 16 million light years to IC4182. This allowed Sandage to calculate the intrinsic brightness of a type-IA supernova also residing in IC4182; this brightness could be compared to that of similar supernovas in more distant galaxies. This distance-finding technique results in a value of 45 for the Hubble constant and an age for the universe of at least 15 billion years. (Science News, 4 July 1992.)