Chemical composition of semi-regular variable giants. II.

N. E. Britavskiy (1) , Sergei Andrievsky (1, 2, 3) , S. A. Korotin (1) , P. Martin (4)

1 Department of Astronomy and Astronomical Observatory, Odessa National University
2 GEPI - Galaxies, Etoiles, Physique, Instrumentation
3 Physique stellaire et galactique
4 WIYN Observatory

Aims: The aim of this work was to derive the elemental abundances in four stars classified as semiregular variables of the type ``d'' (SRd). These stars should presumably belong to the Galactic halo population.
Methods: Elemental abundances have been derived from both local thermodynamical equilibrium (LTE) and non-local thermodynamical equilibrium (NLTE) analyses, applied to high-resolution (R ≅ 80 000) spectra obtained with the CFHT ESPaDOnS spectrograph.
Results: We have derived the abundances of 29 chemical elements in V463 Her, V894 Her, CW CVn, and MS Hya, and arrived at the following conclusions.
Conclusions: The stars of our programme have a chemical composition that does not agree with their presumable status as metal-deficient halo giants. All studied SRd giants have relative-to-solar elemental abundances typical of the thick/thin Galactic disc stars.

Domaines: Astrophysique [astro-ph]

N. E. Britavskiy, Sergei Andrievsky, S. A. Korotin, P. Martin. Chemical composition of semi-regular variable giants. II.. Astronomy and Astrophysics - A&A, 2010, 519, pp.74. ⟨10.1051/0004-6361/201014900⟩. ⟨hal-03729615⟩