Details

Autor(en) / Beteiligte

• Bruntt, H.
• Basu, S.
• Smalley, B.
• Chaplin, W. J.
• Verner, G. A.
• Bedding, T. R.
• Catala, C.
• Gazzano, J.-C.
• Molenda-Żakowicz, J.
• Thygesen, A. O.
• Uytterhoeven, K.
• Hekker, S.
• Huber, D.
• Karoff, C.
• Mathur, S.
• Mosser, B.
• Appourchaux, T.
• Campante, T. L.
• Elsworth, Y.
• García, R. A.
• Handberg, R.
• Metcalfe, T. S.
• Quirion, P.-O.
• Régulo, C.
• Roxburgh, I. W.
• Stello, D.
• Christensen-Dalsgaard, J.
• Kawaler, S. D.
• Kjeldsen, H.
• Morris, R. L.
• Quintana, E. V.
• Sanderfer, D. T.

Titel

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

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2012-06, Vol.423 (1), p.122-131

Ort / Verlag

Oxford, UK: Blackwell Publishing Ltd

Erscheinungsjahr

2012

Quelle

Wiley Online Library

Beschreibungen/Notizen

• 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 α 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 T eff determination with a recent colour calibration of V T−K S [TYCHO V magnitude minus Two Micron All Sky Survey (2MASS) K S 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 i-Fe ii balance, although we find a small systematic offset of 0.08 dex (asteroseismic log g values are lower). The abundance patterns of metals, α 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 α-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.