Research Papers in Physics and Astronomy


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Confrontation between stellar pulsation and evolution; Proceedings of the Conference, Bologna, Italy, May 28-31, 1990 (A91-28876 11-90). San Francisco, CA, Astronomical Society of the Pacific, 1990, p. 193-207; Discussion, p. 207, 208.


Copyright 1990 Astronomical Society of the Pacific


The launch of the Hubble Space Telescope underlines the important role that pulsating stars have played in fundamental astronomical research. Nowhere is this role more crucial than in extragalactic astronomy, where the classical Cepheids have historically served as prime anchor for the cosmic distance scale. Thus it is not surprising that the observation of Cepheids in local and distant galaxies comprises one of three Key Projects approved for HST in the first cycle. The goal is to pin down the Hubble constant to an accuracy of ±10%. In the present review we shall examine how our understanding of galactic Cepheids impacts this goal, including a discussion of the progress that has been made and some of the problems that remain.