@Article{SilvaMiloRoch:2015:HoAbAn,
author = "Silva, Ronaldo da and Milone, Andr{\'e} de Castro and
Rocha-Pinto, H{\'e}lio J.",
affiliation = "{Universit{\`a} di Roma Tor Vergata} and {Instituto Nacional de
Pesquisas Espaciais (INPE)} and {Universidade Federal do Rio de
Janeiro (UFRJ)}",
title = "Homogeneous abundance analysis of FGK dwarf, subgiant, and giant
stars with and without giant planets",
journal = "Astronomy \& Astrophysics",
year = "2015",
volume = "580",
number = "A24",
month = "Aug.",
keywords = "Methods: data analysis, Methods: statistical, Planetary systems,
Stars: abundances, Stars: fundamental parameters, Techniques:
spectroscopic.",
abstract = "Aims. We have analyzed high-resolution and high
signal-to-noise-ratio optical spectra of nearby FGK stars with and
without detected giant planets in order to homogeneously measure
their photospheric parameters, mass, age, and the abundances of
volatile (C, N, and O) and refractory (Na, Mg, Si, Ca, Ti, V, Mn,
Fe, Ni, Cu, and Ba) elements. Our sample contains 309 stars from
the solar neighborhood (up to the distance of 100 pc), out of
which 140 are dwarfs, 29 are subgiants, and 140 are giants.
Methods. The photospheric parameters are derived from the
equivalent widths of Fe? i and Fe? ii lines. Masses and ages come
from the interpolation in evolutionary tracks and isochrones on
the Hertzsprung-Russell diagram. The abundance determination is
based on the equivalent widths of selected atomic lines of the
refractory elements and on the spectral synthesis of C2, CN, C? i,
O? i, and Na? i features. We apply a set of statistical methods to
analyze the abundances derived for the three subsamples. Results.
Our results show that: i) giant stars systematically exhibit
underabundance in [C/Fe] and overabundance in [N/Fe] and [Na/Fe]
in comparison with dwarfs, a result that is normally attributed to
evolution-induced mixing processes in the envelope of evolved
stars; ii) for solar analogs alone, the abundance trends with the
condensation temperature of the elements are correlated with age
and anticorrelated with the surface gravity, which agrees with
recent studies; iii) as in the case of [Fe/H], dwarf stars with
giant planets are systematically enriched in [X/H] for all the
analyzed elements, except for O and Ba (the former due to
limitations of statistics), confirming previous findings in the
literature that it is not only iron that has an important relation
with the planetary formation; and iv) giant planet hosts are also
significantly overabundant for the same metallicity when the
elements from Mg to Cu are combined.",
doi = "10.1051/0004-6361/201525770",
url = "http://dx.doi.org/10.1051/0004-6361/201525770",
issn = "0004-6361 and 1432-0746",
language = "en",
urlaccessdate = "03 jun. 2024"
}