J/ApJ/815/5 Detailed abundances of KOI stars with planets. I. (Schuler+, 2015)
Detailed abundances of stars with small planets discovered by Kepler.
I. The first sample.
Schuler S.C., Vaz Z.A., Katime Santrich O.J., Cunha K., Smith V.V.,
King J.R., Teske J.K., Ghezzi L., Howell S.B., Isaacson H.
<Astrophys. J., 815, 5 (2015)>
=2015ApJ...815....5S 2015ApJ...815....5S (SIMBAD/NED BibCode)
ADC_Keywords: Abundances ; Equivalent widths ; Stars, double and multiple ;
Planets
Keywords: planets and satellites: formation; stars: atmospheres ;
planets and satellites: terrestrial planets; stars: abundances
Abstract:
We present newly derived stellar parameters and the detailed
abundances of 19 elements of seven stars with small planets discovered
by NASA's Kepler Mission. Each star, save one, has at least one planet
with a radius ≤1.6R⊕, suggesting a primarily rocky
composition. The stellar parameters and abundances are derived from
high signal-to-noise ratio, high-resolution echelle spectroscopy
obtained with the 10m Keck I telescope and High Resolution Echelle
Spectrometer using standard spectroscopic techniques. The
metallicities of the seven stars range from -0.32 to +0.13dex, with an
average metallicity that is subsolar, supporting previous suggestions
that, unlike Jupiter-type giant planets, small planets do not form
preferentially around metal-rich stars. The abundances of elements
other than iron are in line with a population of Galactic disk stars,
and despite our modest sample size, we find hints that the
compositions of stars with small planets are similar to stars without
known planets and with Neptune-size planets, but not to those of stars
with giant planets. This suggests that the formation of small planets
does not require exceptional host-star compositions and that small
planets may be ubiquitous in the Galaxy. We compare our derived
abundances (which have typical uncertainties of ≲0.04dex) to the
condensation temperature of the elements; a correlation between the
two has been suggested as a possible signature of rocky planet
formation. None of the stars demonstrate the putative rocky planet
signature, despite at least three of the stars having rocky planets
estimated to contain enough refractory material to produce the
signature, if real. More detailed abundance analyses of stars known to
host small planets are needed to verify our results and place ever
more stringent constraints on planet formation models.
Description:
We have analyzed high-resolution, high-signal-to-noise ratio (S/N)
spectra of seven stars, each of which has at least one confirmed small
planet discovered by Kepler. The spectra of these stars were obtained
as part of the Kepler Follow-up Observing Program (KFOP). The 10m
Keck I telescope and High Resolution Echelle Spectrometer (HIRES) are
being utilized for precise RV measurements of high-priority KOIs. The
KFOP spectra are characterized by a spectral resolution of R=50000 and
span 3650-7950Å with incomplete coverage in the reddest orders.
Additional observations of Kepler-21 were made independently with
Keck/HIRES and the 4m Mayall telescope and echelle spectrograph at
Kitt Peak National Observatory (KPNO) in UT 2011.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 55 10 Observing log
table2.dat 80 9 Stellar parameters
table9.dat 108 12 Lines measured, equivalent widths, and abundances
table10.dat 66 189 Solar lines measured, equivalent widths, and
abundances
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See also:
J/MNRAS/452/2127 : Fundamental param. of Kepler stars (Silva Aguirre+, 2015)
J/ApJ/808/187 : Metallicities of KIC stars without planets (Buchhave+, 2015)
J/ApJ/807/45 : Potentially habitable planet around M dwarfs (Dressing+, 2015)
J/A+A/579/A20 : Circumstellar debris discs (Maldonado+, 2015)
J/A+A/576/A69 : Li abundances in F stars (Delgado+, 2015)
J/ApJS/211/2 : Revised properties of Q1-16 Kepler targets (Huber+, 2014)
J/ApJ/784/45 : Kepler's multiple planet candidates. III. (Rowe+, 2014)
J/ApJS/210/20 : Small Kepler planets radial velocities (Marcy+, 2014)
J/A+A/562/A92 : Li abundance in solar analogues (Delgado Mena+, 2014)
J/A+A/562/A71 : Solar neighbourhood dwarf chemical abundances (Bensby+, 2014)
J/ApJS/210/1 : Asteroseismic study of solar-type stars (Chaplin+, 2014)
J/A+A/561/A7 : Abundances for stars with planets (Ramirez+, 2014)
J/MNRAS/434/1422 : Atmospheric param. of FGKM stars (Molenda-Zakowicz+, 2013)
J/ApJ/771/107 : Spectroscopy of faint KOI stars (Everett+, 2013)
J/ApJ/767/127 : Asteroseismic solutions for 77 Kepler stars (Huber+, 2013)
J/A+A/552/A6 : F-G main-sequence star abundances (Gonzalez Hernandez+, 2013)
J/ApJS/204/24 : Kepler planetary candidates. III. (Batalha+, 2013)
J/ApJ/764/78 : Oxygen abundances in nearby FGK stars (Ramirez+, 2013)
J/A+A/549/A109 : HARPS XXXI. The M-dwarf sample (Bonfils+, 2013)
J/A+A/547/A36 : Chemical abundances of 87 KOIs (Adibekyan++, 2012)
J/ApJ/757/161 : Spectroscopy of 56 exoplanet host stars (Torres+, 2012)
J/ApJ/756/46 : Lithium abundances in HIP stars (Ramirez+, 2012)
J/A+A/545/A32 : Chemical abundances of 1111 FGK stars (Adibekyan+, 2012)
J/other/Nat/486.375 : Stellar parameters of KOI stars (Buchhave+, 2012)
J/MNRAS/423/122 : Abundances of 93 solar-type Kepler targets (Bruntt+, 2012)
J/ApJ/749/152 : Asteroseismic analysis of 22 solar-type stars (Mathur+, 2012)
J/ApJ/749/15 : The Kepler-20 planetary system (Gautier+, 2012)
J/PASP/124/164 : New lithium measures in metal-poor stars (Schaeuble+, 2012)
J/ApJ/736/19 : Kepler planetary candidates. II. (Borucki+, 2011)
J/ApJ/732/55 : Abundances of stars with planets (Schuler+, 2011)
J/ApJ/725/2349 : C/O vs Mg/Si of planetary systems (Delgado Mena+, 2010)
J/ApJ/724/154 : Lithium abundances in stars with planets (Ghezzi+, 2010)
J/ApJ/720/1290 : Abundances of stars hosting planets (Ghezzi+, 2010)
J/ApJ/622/1102 : The planet-metallicity correlation. (Fischer+, 2005)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Kepler Kepler name
12- 14 I3 --- KOI [41/975] KOI number
16- 23 I8 --- KIC KIC number
25- 28 F4.1 mag Kpmag [8.2/12.5] Kepler magnitude from
Borucki et al. (2011, J/ApJ/736/19)
30- 40 A11 "Y/M/D" Date UT observation date
42- 44 I3 --- S/N [160/482]? Signal to noise ratio estimates
given at 6700Å unless flagged
46 A1 --- f_S/N Flag on S/N (1)
48- 55 A8 --- Comm Comment
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Note (1): Flag as follows:
c = S/N at 6850Å.
d = S/N of combined FOP/Keck spectra.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Kepler Kepler name
12- 15 I4 K Teff [5406/6240] Effective temperature
17- 18 I2 K e_Teff [25/45] Teff uncertainty
20- 23 F4.2 [cm/s2] logg [3.9/4.6] Log of surface gravity
25- 28 F4.2 [cm/s2] e_logg [0.08/0.2] logg uncertainty
30- 33 F4.2 km/s Xi [1.1/2] Microturbulent velocity
35- 38 F4.2 km/s e_Xi [0.04/0.2] Xi uncertainty
40- 45 F6.3 --- [FeI/H] [-0.4/0.2] Abundance of [FeI/H]
47- 48 I2 --- NFeI [41/65] Number of [FeI/H] lines
50- 54 F5.3 --- e_[FeI/H] [0.003/0.007] Uncertainty in the mean
abundance (σµ)
56- 61 F6.3 --- [FeII/H] [-0.4/0.2] Abundance of [FeII/H]
63- 64 I2 --- NFeII [5/14] Number of [FeII/H] lines
66- 70 F5.3 --- e_[FeII/H] [0.009/0.03] Uncertainty in the mean
abundance (σµ)
72- 80 A9 --- Comm Comment
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Byte-by-byte Description of file: table9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Ion Ion designation
7- 13 F7.2 0.1nm lambda [5052.1/7775.4] Wavelength in Angstroms
15 A1 --- f_lambda [a] a = Not corrected for Ni blend
17- 20 F4.2 eV ExPot [0/9.2] Excitation potential
22- 27 F6.3 [-] log(gf) [-9.8/0.4] Log oscillator strength
29- 33 F5.1 10-13m EW-K-20 ? Kepler-20 equivalent width (2)
35- 38 F4.2 [-] logN-K-20 ? Kepler-20 log number abundance
40 A1 --- f_logN-K-20 [b] b = Not corrected for hfs
42- 46 F5.1 10-13m EW-K-21 ? Kepler-21 equivalent width (2)
48- 51 F4.2 [-] logN-K-21 ? Kepler-21 log number abundance
53- 57 F5.1 10-13m EW-K-22 ? Kepler-22 equivalent width (2)
59- 62 F4.2 [-] logN-K-22 ? Kepler-22 log number abundance
64- 68 F5.1 10-13m EW-K-37 ? Kepler-37 equivalent width (2)
70- 73 F4.2 [-] logN-K-37 ? Kepler-37 log number abundance
75 A1 --- f_logN-K-37 [b] b = Not corrected for hfs
77- 81 F5.1 10-13m EW-K-68 ? Kepler-68 equivalent width (2)
83- 86 F4.2 [-] logN-K-68 ? Kepler-68 log number abundance
88- 92 F5.1 10-13m EW-K-100 ? Kepler-100 equivalent width (2)
94- 97 F4.2 [-] logN-K-100 ? Kepler-100 log number abundance
99-103 F5.1 10-13m EW-K-130 ? Kepler-130 equivalent width (2)
105-108 F4.2 [-] logN-K-130 ? Kepler-130 log number abundance
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Note (2): In units of milli-Angstroms.
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Byte-by-byte Description of file: table10.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Ion Ion designation
7- 13 F7.2 0.1nm lambda [4620.5/7775.4] Wavelength in Angstroms
15- 15 A1 --- f_lambda [a] a = Not corrected for Ni blend
17- 20 F4.2 eV ExPot [0/9.2] Excitation potential
22- 27 F6.3 [-] log(gf) [-9.8/0.4] Log oscillator strength
29- 33 F5.1 10-13m EW-1 [5.1/168.3] Solar equivalent width from
Kepler-20, -21, & -22 set in mÅ units
35- 38 F4.2 [-] logN-1 [3/8.9] Solar log number abundance from
Kepler-20, -21, & -22
40 A1 --- f_logN-1 [b] b = Not corrected for hfs
42- 46 F5.1 10-13m EW-2 [4.4/157.3]? Solar equivalent width from
Kepler-37, & -68 set in mÅ units
48- 51 F4.2 [-] logN-2 [3/8.9]? Solar log number abundance from
Kepler-37, & -68 set
53 A1 --- f_logN-2 [b] b = Not corrected for hfs
55- 59 F5.1 10-13m EW-3 [4.8/152.7]? Solar equivalent width from
Kepler-100 & -130 set in mÅ units
61- 64 F4.2 [-] logN-3 [3/8.9]? Solar log number abundance from
Kepler-100 & -130 set
66 A1 --- f_logN-3 [b] b = Not corrected for hfs
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 04-Mar-2016