J/AJ/154/107 California-Kepler Survey (CKS). I. 1305 stars (Petigura+, 2017)
The California-Kepler Survey. I. High-resolution spectroscopy of 1305 stars
hosting Kepler transiting planets.
Petigura E.A., Howard A.W., Marcy G.W., Johnson J.A., Isaacson H.,
Cargile P.A., Hebb L., Fulton B.J., Weiss L.M., Morton T.D., Winn J.N.,
Rogers L.A., Sinukoff E., Hirsch L.A., Crossfield I.J.M.
<Astron. J., 154, 107-107 (2017)>
=2017AJ....154..107P 2017AJ....154..107P (SIMBAD/NED BibCode)
ADC_Keywords: Planets ; Rotational velocities ; Radial velocities ;
Effective temperatures ; Abundances, [Fe/H]
Keywords: binaries: spectroscopic - catalogs - stars: abundances -
stars: fundamental parameters
Abstract:
The California-Kepler Survey (CKS) is an observational program
developed to improve our knowledge of the properties of stars found to
host transiting planets by NASA's Kepler Mission. The improvement
stems from new high-resolution optical spectra obtained using HIRES at
the W. M. Keck Observatory. The CKS stellar sample comprises 1305
stars classified as Kepler objects of interest, hosting a total of
2075 transiting planets. The primary sample is magnitude-limited
(Kp<14.2) and contains 960 stars with 1385 planets. The sample was
extended to include some fainter stars that host multiple planets,
ultra-short period planets, or habitable zone planets. The
spectroscopic parameters were determined with two different codes, one
based on template matching and the other on direct spectral synthesis
using radiative transfer. We demonstrate a precision of 60K in Teff,
0.10dex in logg, 0.04dex in [Fe/H], and 1.0km/s in Vsini. In this
paper, we describe the CKS project and present a uniform catalog of
spectroscopic parameters. Subsequent papers in this series present
catalogs of derived stellar properties such as mass, radius, and age;
revised planet properties; and statistical explorations of the
ensemble. CKS is the largest survey to determine the properties of
Kepler stars using a uniform set of high-resolution, high
signal-to-noise ratio spectra. The HIRES spectra are available to the
community for independent analyses.
Description:
The original goal of the California-Kepler Survey (CKS) project was to
measure the stellar properties of all 997 host stars in the first
large Kepler planet catalog (Borucki et al. 2011, Cat. J/ApJ/736/19).
As the Kepler planet catalogs grew in size (Batalha et al. 2013, Cat.
J/ApJS/204/24; Burke et al. 2014, Cat. J/ApJS/210/19), we decided on a
magnitude limit of Kp<14.2 (Kepler apparent magnitude) for the
primary CKS sample. Most of the spectra were collected during the
2012, 2013, and 2014 observing seasons.
We observed all 1305 stars in the CKS sample with the HIgh-Resolution
Echelle Spectrometer (HIRES) spectrometer at the W. M. Keck
Observatory. We used an exposure meter to stop the exposures after
achieving a signal-to-noise ratio (S/N) of 45 per pixel (90 per
resolution element) at the peak of the blaze function in the spectral
order containing 550nm. The spectral format and HIRES settings were
identical to those used by the California Planet Search (CPS; Howard
et al. 2010ApJ...721.1467H 2010ApJ...721.1467H). This includes the use of the B5/C2 decker
with dimensions of 0.86"*3.5"/0.86"*14.0", resulting in a spectral
resolution of 60000. The spectral coverage extended from 3640 to
7990Å.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 24 1305 California-Kepler Survey (CKS) target stars
table4.dat 27 2075 California-Kepler Survey (CKS) candidate planets
table5.dat 199 1305 Spectroscopic parameters
sp/* . 3915 Individual CKS spectra in FITS format
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/ApJS/229/30 : Revised stellar prop. of Q1-17 Kepler targets (Mathur+, 2017)
J/ApJ/822/86 : False positive probabilit. for Q1-Q17 DR24 KOIs (Morton+, 2016)
J/ApJ/807/170 : Prograde vs retrogade motions. II. KOIs (Holczer+, 2015)
J/ApJS/217/31 : Kepler planetary candidates. VI. 4yr Q1-Q16 (Mullally+, 2015)
J/ApJS/210/19 : Kepler planetary candidates. IV. 22 months (Burke+, 2014)
J/ApJ/787/47 : 106 Kepler ultra-short-period planets (Sanchis-Ojeda+, 2014)
J/ApJ/784/45 : Kepler's multiple planet candidates. III. (Rowe+, 2014)
J/ApJS/204/24 : Kepler planetary candidates. III. (Batalha+, 2013)
J/ApJ/736/19 : Kepler planetary candidates. II. (Borucki+, 2011)
http://california-planet-search.github.io/cks-website/ : CKS web page
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name Star name: mostly Kepler Object of Interest (KOI)
identifier, or Kepler Input Catalog (KIC) number
14 I1 --- Lim [0/1] Magnitude Limited (Kp<14.2)
(0=Not member, or 1=Member) (1)
16 I1 --- Mult [0/1] Multi-planet system (0=Not member, or
1=Member) (2)
18 I1 --- Hab [0/1] Habitable zone system (0=Not member,
or 1=Member) (3)
20 I1 --- USP [0/1] Ultra-Short period Planet (USP) (0=Not member,
or 1=Member) (4)
22 I1 --- Oth [0/1] Other (0=Not member, or 1=Member) (5)
24 I1 --- F [0/1] False positive (includes systems for which all
planet candidates have been dispositioned as false
positives) (0=Not member, or 1=Member) (6)
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Note (1): This sample is defined as all stars with Kp<14.2. We set out to
observe a magnitude-limited sample of KOIs chosen independently of the
number of detected planets or previously measured stellar properties. As
the project progressed, we added additional samples of fainter stars.
Note (2): This sample is defined as KOI stars orbited by two or more transiting
planets (excluding false positives). We also observed nearly all of the
multi-transiting systems appearing in the Rowe et al. 2014
(Cat. J/ApJ/784/45) catalog, with priority given to the highest
multiplicity systems and the brightest stars. CKS Paper V (Weiss et al.
2017, submitted) performs a detailed analysis of the multi-planet systems.
Note (3): We observed 127 host stars of Kepler planets residing in or near the
habitable zone defined by Kopparapu et al. 2013ApJ...765..131K 2013ApJ...765..131K. Some of the
individual habitable zone planets have been studied extensively and
validated (Borucki et al. 2013Sci...340..587B 2013Sci...340..587B; Jenkins et al.
2015AJ....150...56J 2015AJ....150...56J; Torres et al. 2015ApJ...800...99T 2015ApJ...800...99T). It is not clear
what to adopt as the boundaries of the liquid-water habitable zone, because
of the many uncertainties in exoplanet atmospheric properties and other
factors that impact planet habitability (Seager 2013Sci...340..577S 2013Sci...340..577S). The
NASA Kepler Team constructed a list of habitable zone targets using the
best available stellar parameters at the time. They selected stars for
which the flux received by the planet fell (within 1σ) between the
Venus and "early-Mars" habitable zone boundaries (Kopparapu et al.
2013ApJ...765..131K 2013ApJ...765..131K). After the revision to the stellar parameters based on
our CKS spectra, we now know that some of these planets are well outside of
the habitable zone. CKS Paper II (Johnson et al. 2017, Cat. J/AJ/154/108)
gives the newly determined values for stellar flux and planetary
equilibrium temperature for all the CKS stars.
Note (4): USP planets (Sanchis-Ojeda et al. 2014, Cat. J/ApJ/787/47) have
orbital periods shorter than one day. Winn et al. 2017AJ....154...60W 2017AJ....154...60W have
performed an investigation of this sample, in particular on the metallicity
distribution.
Note (5): We observed 38 additional Kepler planet host stars for reasons that do
not fall into any of the preceding categories. Often these ad hoc
observations were for studies of unusual or noteworthy planetary systems
(e.g., Kruse & Agol 2014Sci...344..275K 2014Sci...344..275K; Dawson et al. 2015ApJ...798...66D 2015ApJ...798...66D;
Desert et al. 2015ApJ...804...59D 2015ApJ...804...59D; Holczer et al. 2015,
Cat. J/ApJ/807/170).
Note (6): The planetary candidate status ("disposition") of some KOIs has
changed over time. Inevitably, we observed KOIs that are now recognized as
false positives. For completeness, we report on the parameters for these
false positives. Importantly, though, the false positives were not used for
the cross-calibration between our two spectroscopic analysis pipelines (see
Section 4.2). More details on this sample are given in Section 2.5.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Planet name: mostly Kepler Object of Interest
(KOI) identifier, or Kepler Input Catalog (KIC)
identifier
17- 18 A2 --- Disp Adopted disposition (CP, PC, or FP) (1)
20- 21 A2 --- M16 Morton et al. 2016 (Cat. J/ApJ/822/86) false
positive assessment (CP, PC, or FP) (1)
23- 24 A2 --- M15 Mullally et al. 2015 (Cat. J/ApJS/217/31)
false positive assessment (CP, PC, FP, or ND) (1)
26- 27 A2 --- NEA NASA Exoplanet Archive (accessed 2017 February 1:
http://exoplanetarchive.ipac.caltech.edu) false
positive assessment (CP, PC, or FP) (1)
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Note (1): The disposition codes are defined as below:
CP = Confirmed Planet;
PC = Planet Candidate;
FP = False Positive.
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name Star name: mostly Kepler Object of Interest
(KOI) identifier, or Kepler Input Catalog
(KIC) number
14- 23 A10 --- Obs Observation identifier
25- 28 I4 --- Kepler ? Kepler number
30- 33 A4 --- f_Kepler "None" flag on Kepler
35- 42 I8 --- KIC [757450/12737015]? Kepler Input Catalog (KIC)
identifier
44- 49 F6.1 K Teff [4617/6657]? Adopted effective temperature (7)
51- 54 F4.1 K e_Teff [60]? Uncertainty in Teff (8)
56- 60 F5.3 [cm/s2] logg [2.9/4.8]? Adopted log surface gravity (7)
62- 66 F5.3 [cm/s2] e_logg [0.1/0.1]? Uncertainty in logg (8)
68- 73 F6.3 [Sun] [Fe/H] [-0.607/0.465]? Adopted metallicity (7)
75- 79 F5.3 [Sun] e_[Fe/H] [0.04/0.04]? Uncertainty in [Fe/H] (8)
81- 85 F5.1 km/s vsini [0/456.7]? Adopted rotational velocity (7)
87- 89 F3.1 km/s e_vsini [1]? Uncertainty in vsini (8)
91- 95 A5 --- Cat Catalog(s) used for adopted values
(SM=SpecMatch, SX=SME@XSEDE, or SM+SX)
97-102 F6.1 K MTeff [4617.7/6631]? SpecMatch effective temperature
104-108 F5.3 [cm/s2] Mlogg [2.899/4.794]? SpecMatch log surface gravity
110-115 F6.3 [Sun] M[Fe/H] [-0.687/0.44]? SpecMatch metallicity
117-121 F5.1 km/s Mvsini [0/456.7]? SpecMatch rotational velocity
123-128 F6.1 K XTeff [4047/6682]? Spectroscopy Made Easy
(SME)@XSEDE effective temperature (9)
130-134 F5.3 [cm/s2] Xlogg [2.8/5.4]? SME@XSEDE log surface gravity (9)
136-141 F6.3 [Sun] X[Fe/H] [-1.3/1]? SME@XSEDE metallicity (9)
143-146 F4.1 km/s Xvsini [-0.7/21.2]? SME@XSEDE rotational velocity (9)
148-153 F6.1 km/s TRV [-221.6/169.5]? Systemic radial velocity
(relative to solar system barycenter)
155-159 A5 --- BTeff Boolean key for effective temperature
(False or True=effective temperature is
between 4700 and 6500K)
161-165 A5 --- Bvsini Boolean key for vsini (False or True=vsini is
between 0 and 20km/s)
167 I1 --- B [0/2]? Boolean key for pipeline agreement
(0, 1, or 2) (10)
169-199 A31 --- File Name of the FITS file in subdirectory sp;
column added by CDS
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Note (7): Adopted values are our best determination of the spectroscopic
parameters after calibrating the SME@XSEDE values and averaging with the
SpecMatch values.
Note (8): Uncertainties for the adopted values are summarized in Table6 and
Section 4.7.
Note (9): After the calibrations described in Section 4.2.
Note (10): The agreement codes are defined as follows:
0 = SpecMatch (SM) and SME@XSEDE (SX) disagree;
1 = SM and SX agree;
2 = If comparison is not possible.
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History:
From electronic version of the journal
12-Mar-2018:Insert into VizieR
21-Feb-2019: spectra downloaded at:
http://california-planet-search.github.io/cks-website/
References:
Johnson et al., Paper II 2017AJ....154..108J 2017AJ....154..108J, Cat. J/AJ/154/108
Fulton et al., Paper III 2017AJ....154..109F 2017AJ....154..109F, Cat. J/AJ/154/109
Petigura et al., Paper IV 2018AJ....155...89P 2018AJ....155...89P, Cat. J/AJ/155/89
Weiss et al., Paper V 2018AJ....155...48W 2018AJ....155...48W, Cat. J/AJ/155/48
Weiss et al., Paper VI 2018AJ....156..254W 2018AJ....156..254W
Fulton & Petigura., Paper VII 2018AJ....156..264F 2018AJ....156..264F
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 30-Nov-2017