J/ApJ/737/L32 Abundances of 16 Cyg A and B (Schuler+, 2011)
Detailed abundances of the solar twins 16 Cygni A and B: constraining planet
formation models.
Schuler S.C., Cunha K., Smith V.V., Ghezzi L., King J.R., Deliyannis C.P.,
Boesgaard A.M.
<Astrophys. J., 737, L32 (2011)>
=2011ApJ...737L..32S 2011ApJ...737L..32S
ADC_Keywords: Abundances ; Equivalent widths ; Stars, double and multiple
Keywords: planetary systems - planets and satellites: formation -
stars: abundances - stars: atmospheres -
stars: individual (16 Cyg A, 16 Cyg B)
Abstract:
Results of a detailed abundance analysis of the solar twins 16 Cyg A
and 16 Cyg B based on high-resolution, high signal-to-noise ratio
echelle spectroscopy are presented. 16 Cyg B is known to host a giant
planet while no planets have yet been detected around 16 Cyg A.
Stellar parameters are derived directly from our high-quality spectra,
and the stars are found to be physically similar, with
ΔTeff=+43K, Δlogg=-0.02dex, and Δξ=+0.10km/s
(in the sense of A-B), consistent with previous findings. Abundances
of 15 elements are derived and are found to be indistinguishable
between the two stars. The abundances of each element differ by
≤0.026dex, and the mean difference is +0.003±0.015(σ) dex.
Aside from Li, which has been previously shown to be depleted by a
factor of at least 4.5 in 16 Cyg B relative to 16 Cyg A, the two stars
appear to be chemically identical. The abundances of each star
demonstrate a positive correlation with the condensation temperature
of the elements (Tc); the slopes of the trends are also
indistinguishable. In accordance with recent suggestions, the positive
slopes of the [m/H]-Tc relations may imply that terrestrial planets
have not formed around either 16 Cyg A or 16 Cyg B.
Description:
Abundances of 15 elements have been derived from high-resolution, high
signal-to-noise ratio (S/N) spectroscopy of 16 Cyg A and B obtained
with the 10m Keck I telescope and HIRES echelle spectrograph (UT 1994
July 30). The spectra are characterized by a nominal resolution of
R=45000 and S/N at the continuum near λ6700 of 750 and 1050 for
16 Cyg A and 16 Cyg B, respectively.
Objects:
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RA (2000) DE Designation(s)
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19 41 48.95 +50 31 30.2 16 Cyg A = HD 186408
19 41 51.97 +50 31 03.1 16 Cyg B = HD 186427
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 58 130 Lines measured, equivalent widths, and abundances
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See also:
J/AZh/88/530 : Dynamical study of ADS 12815 (Kiselev+, 2011)
J/A+A/526/A71 : C abundances in G and K nearby stars (Da Silva+, 2011)
J/A+A/525/A71 : Atmospheric parameters for 1273 stars (Wu+, 2011)
J/MNRAS/414/1227 : Mg/Fe ratio of MILES stars (Milone+, 2011)
J/MNRAS/396/1895 : MgI and sTiO index definitions (Cenarro+, 2009)
J/A+A/508/L17 : Abundances in solar analogs (Ramirez+, 2009)
J/AZh/84/997 : Abundances of Sr, Y, Zr, Ce and Ba (Mashonkina+, 2007)
J/ApJS/169/430 : Atmospheric parameters of metal-rich stars (Robinson+, 2007)
J/PASJ/57/65 : CNO abundances of solar-type stars (Takeda+, 2005)
J/PASJ/57/45 : Lithium abundances of F-K stars (Takeda+, 2005)
J/AZh/82/453 : Cat. of spectroscopic abundances in stars (Borkova+, 2005)
J/A+A/438/139 : Abundances in Milky Way's disk (Soubiran+, 2005)
J/A+A/423/683 : Sodium abundances in nearby disk stars (Shi+, 2004)
J/AZh/81/541 : Abundances of 15 solar analogues (Galeev+, 2004)
J/AJ/128/1177 : Galactic stellar abundances (Venn+, 2004)
J/MNRAS/340/304 : [X/Fe] of Galactic disc F and G dwarfs (Reddy+, 2003)
J/PASP/113/1365 : Super-metal-rich stars (Buzzoni+, 2001)
J/A+AS/137/521 : 8500-8750Å high resolution spectroscopy (Munari+, 1999)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Ion Ion
7- 13 F7.2 0.1nm lambda Wavelength in Angstroms λ(Å)
15- 18 F4.2 eV ExPot Excitation potential χ
20- 25 F6.3 [-] log(gf) Log of the oscillator strength
27- 31 F5.1 0.1pm EWS Equivalent width in the solar spectrum (mÅ)
33- 36 F4.2 [-] logNS Log of solar number abundance
38- 42 F5.1 0.1pm EWA ? Equivalent width in the 16 Cyg A (mÅ)
44- 47 F4.2 [-] logNA ? Log of 16 Cyg A number abundance
49- 53 F5.1 0.1pm EWB ? Equivalent width in the 16 Cyg B (mÅ)
55- 58 F4.2 [-] logNB ? Log of 16 Cyg B number abundance
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 11-Jan-2013