Bibcode
Aguado, D. S.; Allende Prieto, C.; González Hernández, J. I.; Rebolo, R.
Bibliographical reference
The Astrophysical Journal Letters, Volume 854, Issue 2, article id. L34, 4 pp. (2018).
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2
2018
Citations
48
Refereed citations
45
Description
Only a handful of stars have been identified with an iron abundance
[Fe/H] <‑5, and only one at [Fe/H] <‑7. These stars
have very large carbon-to-iron ratios, with
{\boldsymbol{A}}({\boldsymbol{C}}) ∼ 7.0, most likely due to
fallback in core-collapse supernovae, which makes their total
metallicity Z much higher than their iron abundances. The failure to
find population III stars, those with no metals, has been interpreted,
with support from theoretical modeling, as the result of a top-heavy
initial mass function. With zero or very low metal abundance limiting
radiative cooling, the formation of low-mass stars could be inhibited.
Currently, the star SDSS J1029+1729 sets the potential metallicity
threshold for the formation of low-mass stars at {log}Z/{Z}ȯ
∼ -5. In our quest to push down the metallicity threshold we
have identified SDSS J0023+0307, a primitive star with T eff
= 6188 ± 84 K, and {log}g=4.9+/- 0.5, an upper limit [Fe/H] <‑6.6, and a carbon abundance A(C) < 6.3. We find J0023+0307 to
be one of the two most iron-poor stars known, and it exhibits less
carbon that most of the stars at [Fe/H] <‑5.
Based on observations made with William Herschel Telescope (WHT) and the
Gran Telescopio de Canarias (GTC), at the Observatorio del Roque de los
Muchachos of the Instituto de Astrofísica de Canarias, in La
Palma.
Related projects
Chemical Abundances in Stars
Stellar spectroscopy allows us to determine the properties and chemical compositions of stars. From this information for stars of different ages in the Milky Way, it is possible to reconstruct the chemical evolution of the Galaxy, as well as the origin of the elements heavier than boron, created mainly in stellar interiors. It is also possible to
Carlos
Allende Prieto