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A grid of S stars M...
A grid of S stars MARCS model atmospheres
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- Van Eck, S. (författare)
- Université Libre de Bruxelles, Belgien
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Neyskens, P. (författare)
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Plez, B. (författare)
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Jorissen, A. (författare)
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- Edvardsson, Bengt (författare)
- Uppsala universitet,Teoretisk astrofysik
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- Eriksson, Kjell (författare)
- Uppsala universitet,Teoretisk astrofysik
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- Gustafsson, Bengt (författare)
- Uppsala universitet,Teoretisk astrofysik
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Gråe Jørgensen, U. (författare)
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Nordlund, Å. (författare)
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(creator_code:org_t)
- 2011-12-12
- 2011
- Engelska.
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Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 328, s. 012009-
- Relaterad länk:
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https://doi.org/10.1...
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https://urn.kb.se/re...
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https://doi.org/10.1...
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https://urn.kb.se/re...
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Abstract
Ämnesord
Stäng
- S stars are cool stars of temperatures similar to those of M giants, but their atmospheres are enriched in carbon and s-process elements because of either extrinsic pollution by a binary companion or intrinsic nucleosynthesis and dredge-up on the thermally-pulsing AGB. Despite numerous attempts to link phenomenological spectral classification criteria to physical parameters (T$_eff$, gravity, C/O, [s/Fe], [Fe/H]), the parameter space of S stars is poorly known and this has prevented accurate abundance analysis of S stars until now. Here we present a large grid of S-star model atmospheres. ZrO and TiO band strength indices as well as VJHKL photometry are needed to disentangle the effective temperature, C/O and [s/Fe]. The stellar parameters derived on the basis of low-resolution spectra and photometry are shown to be fairly accurate when compared to high-resolution data of the same stars. The C/O ratio of S stars is found to be between the solar value (0.5) and 0.99, and not 1 as often claimed in the literature. Consistently with stellar evolution expectations, the C/O ratio increases as the effective temperature decreases.
Ämnesord
- NATURVETENSKAP -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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