uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
A grid of S stars MARCS model atmospheres
Show others and affiliations
2011 (English)In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 328, 012009- p.Article in journal (Refereed) Published
Abstract [en]

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.

Place, publisher, year, edition, pages
2011. Vol. 328, 012009- p.
National Category
Astronomy, Astrophysics and Cosmology
URN: urn:nbn:se:uu:diva-169741DOI: 10.1088/1742-6596/328/1/012009OAI: oai:DiVA.org:uu-169741DiVA: diva2:507837
Available from: 2012-03-06 Created: 2012-03-05 Last updated: 2012-11-02Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Edvardsson, BengtEriksson, KjellGustafsson, Bengt
By organisation
Theoretical Astrophysics
In the same journal
Journal of Physics, Conference Series
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 461 hits
ReferencesLink to record
Permanent link

Direct link