Fechar
Metadados

@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 = "04 dez. 2020"
}


Fechar