J/ApJ/839/94 Abundances of solar twins from Keck/HIRES (Bedell+, 2017)
Kepler-11 is a solar twin: revising the masses and radii of benchmark planets
via precise stellar characterization.
Bedell M., Bean J.L., Melendez J., Mills S.M., Fabrycky D.C., Freitas F.C.,
Ramirez I., Asplund M., Liu F., Yong D.
<Astrophys. J., 839, 94-94 (2017)>
=2017ApJ...839...94B 2017ApJ...839...94B (SIMBAD/NED BibCode)
ADC_Keywords: Abundances, [Fe/H] ; Equivalent widths ; Stars, G-type
Keywords: planets and satellites: fundamental parameters; stars: abundances;
stars: fundamental parameters; techniques: spectroscopic
Abstract:
The six planets of the Kepler-11 system are the archetypal example of
a population of surprisingly low-density transiting planets revealed
by the Kepler mission. We have determined the fundamental parameters
and chemical composition of the Kepler-11 host star to unprecedented
precision using an extremely high-quality spectrum from Keck-HIRES
(R∼67000, S/N per pixel ∼260 at 600nm). Contrary to previously
published results, our spectroscopic constraints indicate that
Kepler-11 is a young main-sequence solar twin. The revised stellar
parameters and new analysis raise the densities of the Kepler-11
planets by between 20% and 95% per planet, making them more typical of
the emerging class of "puffy" close-in exoplanets. We obtain
photospheric abundances of 22 elements and find that Kepler-11 has an
abundance pattern similar to that of the Sun with a slightly higher
overall metallicity. We additionally analyze the Kepler light curves
using a photodynamical model and discuss the tension between
spectroscopic and transit/TTV-based estimates of stellar density.
Description:
Over the course of two consecutive nights (2015 July 26-27), we made
22 exposures of Kepler-11 of 1200s each for a coadded result of
S/N∼260 per pixel in the continuum near 600nm. For these observations,
HIRES was used with a resolution R∼67000 and wavelength coverage
between 390 and 830nm.
We also observed the solar spectrum (via reflection from Ceres) and
nine bright potential Kepler-11 twins with the same instrumental setup
and similar S/N.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 103 687 Line list and measured equivalent widths
table2.dat 60 11 Summary of derived fundamental stellar properties
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See also:
I/315 : UCAC3 Catalogue (Zacharias+ 2009)
J/MNRAS/367/1329 : Elemental abundances for 176 stars (Reddy+, 2006)
J/A+A/465/271 : Oxygen abundances in nearby stars (Ramirez+, 2007)
J/A+A/503/541 : Neutral Li in late-type stars non-LTE calc. (Lind+, 2009)
J/ApJ/709/447 : Chemical composition of OGLE-2007-BLG-514S (Epstein+, 2010)
J/A+A/547/A36 : Chemical abundances of 87 KOIs (Adibekyan++, 2012)
J/A+A/545/A32 : Chemical abundances of 1111 FGK stars (Adibekyan+, 2012)
J/ApJ/795/23 : Line list for stellar chemical abundances (Bedell+, 2014)
J/A+A/562/A71 : Abundances of solar neighbourhood dwarfs (Bensby+, 2014)
J/ApJ/783/123 : Surface gravity for 220 Kepler stars (Campante+, 2014)
J/ApJ/784/45 : Kepler's multiple planet candidates. III. (Rowe+, 2014)
J/ApJ/801/L10 : XO-2N and XO-2S equivalent widths (Teske+, 2015)
J/ApJ/806/248 : AO imaging of KOIs with gas giant planets (Wang+, 2015)
J/A+A/592/A156 : The Solar Twin Planet Search. IV. (dos Santos+, 2016)
J/MNRAS/456/2636 : Kepler-10 chemical composition (Liu+, 2016)
http://www.inspect-stars.com/ : Database for interactive NLTE spectroscopy
of late-type stars (INSPECT)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- f_lambda [-] -: Wavelength where EWs are always "0"
2- 10 F9.4 0.1nm lambda [4082.9/7933.2] Wavelength in Angstroms
12- 16 F5.1 --- Sp [6/106] Species identifier (1)
18- 23 F6.4 eV EP [0/9.2] Excitation potential
25- 31 F7.4 [-] log(gf) [-6.2/0.6] Log of the oscillator strength
33- 37 F5.1 10-13m K11 [0/158.1]? Measured equivalent width,
Kepler-11, milli-Angstroms
39- 43 F5.1 10-13m Sun [0/156.5]? Measured equivalent width, the Sun,
milli-Angstroms
45- 49 F5.1 10-13m Sun2 [11.6/123.6]? Measured equivalent width,
the Sun, milli-Angstroms (2)
51- 55 F5.1 10-13m HD1178 [0/169.4]? Measured equivalent width, HD1178,
milli-Angstroms
57- 61 F5.1 10-13m HD10145 [0/163.1]? Measured equivalent width, HD10145,
milli-Angstroms
63- 67 F5.1 10-13m HD16623 [0/142.1]? Measured equivalent width, HD16623,
milli-Angstroms
69- 73 F5.1 10-13m HD20329 [0/170.3] Measured equivalent width, HD20329,
milli-Angstroms
75- 79 F5.1 10-13m HD21727 [0/163]? Measured equivalent width, HD21727,
milli-Angstroms
81- 85 F5.1 10-13m HD21774 [0/172]? Measured equivalent width, HD21774,
milli-Angstroms
87- 91 F5.1 10-13m HD28474 [0/132]? Measured equivalent width, HD28474,
milli-Angstroms
93- 97 F5.1 10-13m HD176733 [0/162.6]? Measured equivalent width, HD176733,
milli-Angstroms
99-103 F5.1 10-13m HD191069 [0/164.3]? Measured equivalent width, HD191069,
milli-Angstroms
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Note (1): Where the number before the decimal is the element number and the
number after the decimal is the ionization state, e.g. 6.0 = C I.
Note (2): Solar equivalent widths used as reference for HD10145, HD21727, and
HD191069 stellar parameters. The remaining stars use the other solar
measurements.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- ID Star name
10 A1 --- f_ID Flag on ID (1)
12- 15 I4 K Teff [5606/5836] Effective temperature
17- 18 I2 K e_Teff [6/29]? Teff uncertainty (σT)
20- 23 F4.2 [cm/s2] logg [4.2/4.5] Surface gravity
25- 31 F7.2 [cm/s2] e_logg [0.02/0.07]? logg uncertainty (σlogg)
33- 36 F4.2 km/s Vt [0.8/1.1] Microturbulence
38- 44 F7.2 km/s e_Vt [0.01/0.06]? Vt uncertainty (σVt)
46- 51 F6.3 [Sun] [Fe/H] [-0.7/0.3] Abundance of [Fe/H]
53- 60 F8.3 [Sun] e_[Fe/H] [0.005/0.03]? [Fe/H] uncertainty
(σ[Fe/H])
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Note (1): Sun (via reflection from Ceres) used as a reference star.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 29-Nov-2017