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On the formation of metal-poor stars
Astrophysics and Space Science, 1974The expulsion of metal-rich grains from collapsing protostars is considered, and it is concluded that stars of mass greater than 21M⊙ could be significantly depleted in heavy metals during their formation.
Michael Edmunds, N. C. Wickramasinghe
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1995
We present new beryllium abundances for 20 metal-poor stars with metallicities ([Fe/H]) in the range −3.1 to −0.3, most of them with [Fe/H] below −1.3. Beryllium abundances were derived from 0.06 A effective resolution spectra via spectral synthesis. Our results show evidence for a strong Be enrichment in the early Galaxy.
Rafael Rebolo +3 more
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We present new beryllium abundances for 20 metal-poor stars with metallicities ([Fe/H]) in the range −3.1 to −0.3, most of them with [Fe/H] below −1.3. Beryllium abundances were derived from 0.06 A effective resolution spectra via spectral synthesis. Our results show evidence for a strong Be enrichment in the early Galaxy.
Rafael Rebolo +3 more
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Abundances in Very Metal-Poor Stars
1999Stars with a metallicity lower than [Fe/H] = −3 are of particular interest since they were formed early in the history of the Galaxy. The chemical compositions of their atmospheres represent the yields of the first massive supernovae (Ryan et al., 1991, 1996).
Spite, M.E. +7 more
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Sulphur Abundances in Metal-poor Stars
2008We report on sulphur abundances in halo stars as derived from near-IR UVES spectra. The importance of removing telluric lines and residual CCD fringing patterns by using early B-type stars as calibrators is emphasized. Comparison of data from the weak λ8694.6 and the stronger λ9212.9, 9237.5 pair of S I lines provides important constraints on non-LTE ...
Nissen, Poul Erik +4 more
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Hydrodynamical Model Atmospheres of Metal‐Poor Stars
AIP Conference Proceedings, 2008Standard one‐dimensional (1D) model atmospheres rely on the assumption of radiative equilibrium in the non‐convective part of the stellar photosphere. However, gas‐dynamical effects can lead to dramatic deviations from radiative equilibrium conditions, especially in metal‐poor stellar atmospheres.
Ludwig, Hans-Günter +4 more
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Observing Boron in Metal-Poor Stars
1999A new sample of 7 stars ranging in metallicity from [Fe/H] = −2.0 to [Fe/H] = −0.75 has been analyzed in the boron spectral region. The targets were selected according to the availability (in the literature) of their lithium and beryllium abundances, because the simultaneous knowledge of LiBeB in the same targets is a powerful diagnostic for testing ...
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NUCLEOSYNTHESIS IN EXTREMELY METAL POOR STARS AND THE ORIGIN OF THE MOST METAL-POOR STAR HE0107-5240
Origin of Matter and Evolution of Galaxies 2003, 2004Takanori Nishimura +3 more
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