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Centro de Astrofísica da Universidade do Porto

Determination of the spectroscopic stellar parameters for 257 field giant stars

S. Alves, L. Benamati, N. C. Santos, V. Zh. Adibekyan, S. G. Sousa, G. Israelian, J. R. de Medeiros, C. Lovis, S. Udry

Abstract
The study of stellar parameters of planet-hosting stars, such as metallicity and chemical abundances, help us to understand the theory of planet formation and stellar evolution. Here, we present a catalogue of accurate stellar atmospheric parameters and iron abundances for a sample of 257 K and G field evolved stars that are being surveyed for planets using precise radial-velocity measurements as part of the Coralie programme to search for planets around giants. The analysis was done using a set of high-resolution and high-signal-to-noise Ultraviolet and Visible Echelle Spectrograph spectra. The stellar parameters were derived using Fe i and ii ionization and excitation equilibrium methods. To take into account possible effects related to the choice of the lines on the derived parameters, we used three different iron line-list sets in our analysis, and the results differ among themselves by a small factor for most of stars. For those stars with previous literature parameter estimates, we found very good agreement with our own values. In the present catalogue, we are providing new precise spectroscopic measurements of effective temperature, surface gravity, microturbulence, and metallicity for 190 stars for which it has not been found or published in previous articles.

Keywords
methods: observational, techniques: spectroscopic, catalogues, stars: fundamental parameters, stars: late-type

Monthly Notices of the Royal Astronomical Society
Volume 448, Page 2749
April 2015

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