J/AJ/152/158 Final Kepler transiting planet search (DR25) (Twicken+, 2016)
Detection of potential transit signals in 17 quarters of Kepler data: results of
the final Kepler mission transiting planet search (DR25).
Twicken J.D., Jenkins J.M., Seader S.E., Tenenbaum P., Smith J.C.,
Brownston L.S., Burke C.J., Catanzarite J.H., Clarke B.D., Cote M.T.,
Girouard F.R., Klaus T.C., Li J., McCauliff S.D., Morris R.L., Wohler B.,
Campbell J.R., Uddin A.K., Zamudio K.A., Sabale A., Bryson S.T.,
Caldwell D.A., Christiansen J.L., Coughlin J.L., Haas M.R., Henze C.E.,
Sanderfer D.T., Thompson S.E.
<Astron. J., 152, 158-158 (2016)>
=2016AJ....152..158T 2016AJ....152..158T (SIMBAD/NED BibCode)
ADC_Keywords: Planets ; Stars, double and multiple
Keywords: planetary systems - planets and satellites: detection
Abstract:
We present results of the final Kepler Data Processing Pipeline search
for transiting planet signals in the full 17-quarter primary mission
data set. The search includes a total of 198709 stellar targets, of
which 112046 were observed in all 17 quarters and 86663 in fewer than
17 quarters. We report on 17230 targets for which at least one transit
signature is identified that meets the specified detection criteria:
periodicity, minimum of three observed transit events, detection
statistic (i.e., signal-to-noise ratio) in excess of the search
threshold, and passing grade on three statistical transit consistency
tests. Light curves for which a transit signal is identified are
iteratively searched for additional signatures after a limb-darkened
transiting planet model is fitted to the data and transit events are
removed. The search for additional planets adds 16802 transit signals
for a total of 34032; this far exceeds the number of transit
signatures identified in prior pipeline runs. There was a strategic
emphasis on completeness over reliability for the final Kepler transit
search. A comparison of the transit signals against a set of 3402
well-established, high-quality Kepler Objects of Interest yields a
recovery rate of 99.8%. The high recovery rate must be weighed against
a large number of false-alarm detections. We examine characteristics
of the planet population implied by the transiting planet model fits
with an emphasis on detections that would represent small planets
orbiting in the habitable zone of their host stars.
Description:
The Kepler spacecraft is in an Earth-trailing heliocentric orbit and
maintained a boresight pointing centered on α=19h22m40s,
δ=+44.5° during the primary mission. The Kepler photometer
acquired data on a 115-square-degree region of the sky. The data were
acquired on 29.4-minute intervals, colloquially known as "long
cadences". Long-cadence pixel values were obtained by accumulating 270
consecutive 6.02s exposures. Science acquisition of Q1 data began at
2009-05-13 00:01:07Z, and acquisition of Q17 data concluded at
2013-05-11 12:16:22Z. This time period contains 71427 long-cadence
intervals. A total of 198709 targets observed by Kepler were searched
for evidence of transiting planets in the final Q1-Q17 pipeline run
(see Table1).
The results of past Kepler Mission transiting planet searches have
been presented in Tenenbaum et al. 2012 (Cat. J/ApJS/199/24) for
Quarter 1 through Quarter 3 (i.e., Q1-Q3), Tenenbaum et al.
2013ApJS..206....5T 2013ApJS..206....5T for Q1-Q12, Tenenbaum et al. 2014ApJS..211....6T 2014ApJS..211....6T
for Q1-Q16, and Seader et al. 2015 (Cat. J/ApJS/217/18) for Q1-Q17. We
now present results of the final Kepler transiting planet search
encompassing the complete 17-quarter primary mission. The data release
for the final Q1-Q17 pipeline processing is referred to as Data
Release 25 (DR25).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 15 198709 Targets searched for transiting planets
table2.dat 9 975 Eclipsing binaries excluded from transiting
planet search
table3.dat 68 3402 Golden Kepler Object of Interest (KOI) and
Threshold Crossing Event (TCE) ephemeris
matching results
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/ApJS/224/12 : Kepler planetary candidates. VII. 48-month (Coughlin+, 2016)
J/AJ/151/68 : Kepler Mission. VII. Eclipsing binaries in DR3 (Kirk+, 2016)
J/ApJ/812/46 : Transit metric for Q1-Q17 Kepler candidates (Thompson+, 2015)
J/ApJ/810/95 : Kepler pipeline S/N studies. II. (Christiansen+, 2015)
J/ApJS/217/31 : Kepler planetary candidates. VI. 4yr Q1-Q16 (Mullally+, 2015)
J/ApJS/217/18 : Potential transit signals in Kepler Q1-Q17 (Seader+, 2015)
J/ApJS/217/16 : Kepler planetary candidates. V. 3yr Q1-Q12 (Rowe+, 2015)
J/AJ/147/119 : Sources in the Kepler field of view (Coughlin+, 2014)
J/ApJS/210/19 : Kepler planetary candidates. IV. 22 months (Burke+, 2014)
J/ApJS/208/16 : Kepler transit timing observations. VIII. (Mazeh+, 2013)
J/ApJS/207/35 : Kepler pipeline signal-to-noise studies (Christiansen+, 2013)
J/ApJS/204/24 : Kepler planetary candidates. III. (Batalha+, 2013)
J/ApJS/199/24 : The first three quarters of Kepler mission (Tenenbaum+, 2012)
J/ApJ/756/185 : Kepler TTVs. V. Metrics catalog (Ford+, 2012)
J/ApJ/736/19 : Kepler planetary candidates. II. (Borucki+, 2011)
J/ApJ/728/117 : Kepler planetary candidates. I. (Borucki+, 2011)
J/AJ/142/160 : Kepler Mission. II. Eclipsing binaries in DR2 (Slawson+, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- KIC [757076/100001645] Identifier in Kepler Input
Catalog (Cat. V/133) (1)
11- 12 I2 --- Nq [1/17] Number of quarters observed
14- 15 I2 --- Ntce [0/10] Number of Threshold Crossing Events
(TCEs) (2)
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Note (1): Targets included in the the final Q1-Q17 pipeline processing (DR25)
transit search. This table is sorted by KIC ID.
Seven of the targets (last seven in the table) searched for transiting
planets were designated as Custom Targets. Such targets are not stellar
objects in the Kepler Input Catalog (KIC, Cat. V/133), but rather represent
regions of pixels in given quarters that were collected in support of a
variety of scientific investigations. Custom Targets were assigned
numerical identifiers outside the range of the Kepler Input Catalog (also
known as the KIC).
Note (2): For the 17230 target stars found to contain a TCE, additional transit
searches were employed to identify potential multiple-planet systems. The
process is described in Wu et al. 2010SPIE.7740E..19W 2010SPIE.7740E..19W, Tenenbaum et al.
2013ApJS..206....5T 2013ApJS..206....5T, and J. D. Twicken et al. (2016, in preparation). The
multiple-planet search incorporates a configurable upper limit on the
number of TCEs per target, which is currently set to 10. This limit was
established for two reasons. First, the limit on TCEs for a given target
was instituted to manage pipeline task processing time. Second, applying a
limit to the number of TCEs per target prevents a failure mode in which a
target flux time series is sufficiently pathological that the search
process becomes "stuck", returning one detection after another. The
selected limit of 10 TCEs is based on experience: the maximum number of
Kepler Objects of Interest (KOIs) to date on a single target star is seven,
which indicates that limiting the process to 10 TCEs per target is unlikely
to sacrifice potential KOIs. The transit searches performed for detection
of TCEs in multiple-planet systems yielded 16802 additional TCEs across
7120 unique target stars, for a total of 34032 TCEs. Please refer to
Section 2.5 for more details about the detection of multiple-planet
systems.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- KIC [1433410/12785282] Kepler identifier (1)
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Note (1): Some known eclipsing binaries have been excluded from planet searches
in the pipeline, as described in Tenenbaum et al. 2014ApJS..211....6T 2014ApJS..211....6T and
Seader et al. 2015 (Cat. J/ApJS/217/18). The pipeline transiting planet
search and data validation algorithms are not well suited to binaries
without detached and well-separated eclipses. A total of 975 known contact
and semidetached eclipsing binaries were excluded from the Q1 to Q17 DR25
search. This table is sorted by KIC ID.
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.2 --- KOI [1.01/6251.1] Kepler Object of Interest (KOI)
number (1)
9- 16 F8.4 d KPer [0.3/550.9] KOI orbital period
18- 25 F8.4 d TPer [-1/550.9] Threshold Crossing Event (TCE)
orbital period (2)
27- 34 F8.4 d KEpoch [120.5/589.8] Barycentric Kepler-modified
Julian Date (BKJD) KOI epoch of first transit (2)
36- 43 F8.4 d TEpoch [-1/491.1] Barycentric Kepler-modified Julian
Date (BKJD) TCE epoch of first transit
45- 52 F8.4 h KDur [0.26/26.5] KOI transit duration
54- 61 F8.4 h TDur [-1/108.7] TCE transit duration (2)
63- 68 F6.3 --- Corr [-1/1] Ephemeris match correlation coefficient (2)
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Note (1): The table is sorted by KOI number.
Note (2): Values are set to -1.0 for golden KOIs that were not recovered in the
DR25 Q1-Q17 transit search.
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 23-Jan-2017