Accurate fundamental parameters and detailed abundance patterns from spectroscopy of 93 solar-type Kepler targets

作者：Bruntt H^*; Basu S; Smalley B; Chaplin W J; Verner G A; Bedding T R; Catala C; Gazzano J C; Molenda Zakowicz J; Thygesen A O; Uytterhoeven K; Hekker S; Huber D; Karoff C; Mathur S; Mosser B; Appourchaux T; Campante T L; Elsworth Y; Garcia R A; Handberg R; Metcalfe T S; Quirion P O; Regulo C; Roxburgh I W; Stello D; Christensen Dalsgaard J; Kawaler S D; Kjeldsen H; Morris R L; Quintana E V; Sanderfer D T

来源：Monthly Notices of the Royal Astronomical Society, 2012, 423(1): 122-131.

DOI：10.1111/j.1365-2966.2012.20686.x

• stars: abundances
• stars: atmospheres
• stars: fundamental parameters
• stars: solar-type

We present a detailed spectroscopic study of 93 solar-type stars that are targets of the NASA/Kepler mission and provide detailed chemical composition of each target. We find that the overall metallicity is well represented by Fe lines. Relative abundances of light elements (CNO) and a elements are generally higher for low-metallicity stars. Our spectroscopic analysis benefits from the accurately measured surface gravity from the asteroseismic analysis of the Kepler light curves. The accuracy on the log g parameter is better than 0.03 dex and is held fixed in the analysis. We compare our Teff determination with a recent colour calibration of VT-KS [TYCHO V magnitude minus Two Micron All Sky Survey (2MASS) KS magnitude] and find very good agreement and a scatter of only 80 K, showing that for other nearby Kepler targets, this index can be used. The asteroseismic log g values agree very well with the classical determination using Fe iFe ii balance, although we find a small systematic offset of 0.08 dex (asteroseismic log g values are lower). The abundance patterns of metals, a elements and the light elements (CNO) show that a simple scaling by [Fe/H] is adequate to represent the metallicity of the stars, except for the stars with metallicity below -0.3, where a-enhancement becomes important. However, this is only important for a very small fraction of the Kepler sample. We therefore recommend that a simple scaling with [Fe/H] be employed in the asteroseismic analyses of large ensembles of solar-type stars.

• 出版日期2012-6
• 单位中国地震局