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  • Print publication year: 2006
  • Online publication date: August 2009

HST abundance studies of low metallicity stars

    • By J. W. Truran, Department of Astronomy & Astrophysics, University of Chicago, C. Sneden, Department of Astronomy and McDonald Observatory, University of Texas, F. Primas, European Southern Observatory, Garching, Germany, J. J. Cowan, Department of Physics & Astronomy, University of Oklahoma, T. Beers, Department of Physics and Astronomy, Michigan State University
  • Edited by Mario Livio, Space Telescope Science Institute, Baltimore, Stefano Casertano, Space Telescope Science Institute, Baltimore
  • Publisher: Cambridge University Press
  • DOI:
  • pp 57-62



Abundance studies of the oldest stars provide critical clues to—and constraints upon—the characteristics of the earliest stellar populations in our Galaxy. Such constraints include those upon: light element production and BBN; the early star-formation and nucleosynthesis history of the Galaxy; the characteristics of heavy-element nucleosynthesis mechanisms; and the ages of early stellar populations from nuclear chronometers. Discussions of many of these issues are to be found in a number of review papers (Wheeler et al. 1989; McWilliam 1997; Truran et al. 2002; Gratton, Sneden, & Caretta 2004).

While much of the available data has been obtained with ground-based telescopes, there is much to learn with HST. Studies in the wavelength region accessible with HST can, in fact, address issues ranging from the origin of the light elements Li, Be, and B to the production mechanisms responsible for the synthesis of the heaviest elements through thorium and uranium. In the following two sections, we will review specifically first boron abundance studies at low Z and then abundances of the heavy elements Ge, Zr, Os, Pt, Au, and Pb, at low Z.

Boron abundances in halo stars

Knowledge of lithium, beryllium, and boron abundances in stars play a major role in our understanding of Big Bang nucleosynthesis, cosmic-ray physics, and stellar interiors.

In the standard model for the origin and evolution of the light elements, only 7Li is produced in significant amounts from Big Bang (primordial) nucleosynthesis.