J/AJ/157/124 DAVE. I. Benchmarking K2 vetting tools (Kostov+, 2019)
Discovery and Vetting of Exoplanets. I. Benchmarking K2 vetting tools.
Kostov V.B., Mullally S.E., Quintana E.V., Coughlin J.L., Mullally F.,
Barclay T., Colon K.D., Schlieder J.E., Barentsen G., Burke C.J.
<Astron. J., 157, 124 (2019)>
=2019AJ....157..124K 2019AJ....157..124K (SIMBAD/NED BibCode)
ADC_Keywords: Exoplanets ; Photometry ; Stars, double and multiple
Keywords: planets and satellites: general - techniques: photometric
Abstract:
We have adapted the algorithmic tools developed during the Kepler mission
to vet the quality of transit-like signals for use on the K2 mission data.
Using the four sets of publicly available light curves at MAST, we produced
a uniformly vetted catalog of 772 transiting planet candidates from K2
as listed at the NASA Exoplanet Archive in the K2 Table of Candidates. Our
analysis marks 676 of these as planet candidates and 96 as false positives.
All confirmed planets pass our vetting tests. Sixty of our false positives
are new identifications, effectively doubling the overall number of
astrophysical signals mimicking planetary transits in K2 data. Most of
the targets listed as false positives in our catalog show either prominent
secondary eclipses, transit depths suggesting a stellar companion instead
of a planet, or significant photocenter shifts during transit. We packaged
our tools into the open-source, automated vetting pipeline Discovery and
Vetting of Exoplanets (DAVE), designed to streamline follow-up efforts
by reducing the time and resources wasted observing targets that are likely
false positives. DAVE will also be a valuable tool for analyzing planet
candidates from NASA's TESS mission, where several guest-investigator
programs will provide independent light-curve sets - and likely many more
from the community. We are currently testing DAVE on recently released
TESS planet candidates and will present our results in a follow-up paper.
Description:
Throughout this work, when available, we use four different sets of K2
light curves in our Discovery and Vetting of Exoplanets (DAVE)
analyses. The four light-curve reductions used are Aigrain et al.
2015MNRAS.447.2880A 2015MNRAS.447.2880A (AGP; Table 4), Luger et al. (2016AJ....152..100L 2016AJ....152..100L;
EVEREST), Vanderburg & Johnson (2014PASP..126..948V 2014PASP..126..948V; k2sff), and the
Kepler/K2 program office-processed light curves (PDC). We used the DAVE
pipeline to vet the K2 Planet Candidate Catalog hosted at the NASA
Exoplanet Archive as of 2018 August 6 utilizing the four publicly
available light curves - AGP, EVEREST, PDC, and SFF - that are available
as high-level science products at MAST. Capitalizing on this treasure
trove of data, we produced a uniformly vetted, publicly available DAVE
catalog of 772 planets using data from K2 Campaigns 1 through 10.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 867 772 DAVE disposition of confirmed planets listed on
NExScI as of 2018 August 6 and the false positives
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See also:
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
J/ApJ/809/25 : Stellar and planet properties for K2 candidates
(Montet+, 2015)
J/A+A/594/A100 : K2 new planetary and EB candidates (Barros+, 2016)
J/ApJS/226/7 : Planet candidates discovered using K2's 1st yr
(Crossfield+, 2016)
J/AJ/154/107 : California-Kepler Survey (CKS). I. 1305 stars
(Petigura+, 2017)
J/AJ/154/207 : K2 planetary systems orbiting low-mass stars
(Dressing+, 2017)
J/AJ/154/224 : Transiting planets in young clusters from K2
(Rizzuto+, 2017)
J/ApJ/847/18 : Mass, Z, dust attenuation, and SFR relations (Zahid+, 2017)
J/MNRAS/465/2634 : Kepler and K2 best candidates for planets (Armstrong+, 2017)
J/AJ/155/21 : Planet candidates from K2 campaigns 5-8 (Petigura+, 2018)
J/AJ/155/136 : Planets orbiting bright stars in K2 campaigns 0-10
(Mayo+, 2018)
J/AJ/156/78 : 44 validated planets from K2 Campaign 10 (Livingston+, 2018)
http://keplertcert.seti.org/DAVE/ : Discovery and Vetting of K2 Exoplanets
(DAVE) website
http://nexsci.caltech.edu/ : NASA Exoplanet Science Institute (NExScI) website
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- EPIC [201092629/229131722] EPIC identfier
11- 16 F6.3 d Per [0.252/80] Orbital period
18- 28 F11.6 --- Epoch [1995.363042/2801.12168] Epoch
30-196 A167 --- AGP AGP lightcurve automated false positive reason (1)
198-355 A158 --- EVE EVEREST lightcurve automated false positive reason
(1)
357-514 A158 --- PDC PDC lightcurve automated false positive reason (1)
516-673 A158 --- SFF SFF lightcurve automated false positive reason (1)
675-676 A2 --- Final [FP/PC] Final disposition in DAVE catalog (1)
678-687 A10 --- FP False positive reason (1)
689-719 A31 --- NExScI NExScI disposition (1)
721-813 A93 --- Com Comments (1)
815-867 A53 --- Plots Display summary plots from the DAVE catalog
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Note (1): Abbreviations used in table:
A16 = Adams et al. (2016AJ....152...47A 2016AJ....152...47A);
AGP = AGP lightcurves (Aigrain et al. 2015MNRAS.447.2880A 2015MNRAS.447.2880A);
B16 = Barros et al. (2016, J/A+A/594/A100);
BAD VET = Bad Vetting. Something is wrong with the vetting, e.g.
a module failed due to difficult lightcurve;
C16 = Crossfield et al. (2016, J/ApJS/226/7);
C17 = Cabrera et al. (2017A&A...606A..75C 2017A&A...606A..75C);
CO = Centroid Offset. DAVE finds a significant centroid offset;
COSp = Centroid Offset Spurious. Either the difference centroid and
the out-of-transit centroid are within 3-σ distance of
each other, or very few points, or very few transits, or a
combination of;
CP = Confirmed Planet;
D17 = Dressing et al. (2017, J/AJ/154/207);
(D)LC = (Difficult) LightCurve. Light curve looks very noisy and/or
has high variability, the transits are difficult to see and
DAVE may not be able to provide proper vetting;
EVE = EVEREST lightcurves (Luger et al. 2016AJ....152..100L 2016AJ....152..100L,
2018AJ....156...99L 2018AJ....156...99L);
FP = False Positive;
FSAp = Field Star(s) in Aperture;
FSApST = Field Star(s) in Aperture, the Source of the Transit;
ITD = Inconsistent Transit Depth;
L18 = Livingston et al. (2018, J/AJ/156/78);
LCMOD = LightCurve Modulations, feature not transit-like, potential
stellar variability;
M15 = Montet et al. (2015, J/ApJ/809/25);
M18 = Mayo et al. (2018, J/AJ/155/136);
N/A = Disposition and/or Lightcurve Not Available;
NC = Not Convincing;
LCMOD = Lightcurve Modulations;
MULTI = Multiplanet system. Important to keep in mind when DAVE finds
a centroid offset (CO) for only one planet in a multiplanet
system;
N/A = No Data Available;
NC = Not Convincing. DAVE status does not look convincing under
closer inspection. For example, an ODD-EVEN difference is
probably not real due to very deep transit/eclipse;
NSAp = Nothing Suspicious in Aperture;
OE = Odd-Even difference between consecutive transits; potential
EB;
OOTCAS = Out-of-transit Centroid locks on Another Star;
OOTMOD = Out-of-Transit Modulations in-phase (or nearly so) with the
transits, potential EB;
P16 = Pope et al. (2016MNRAS.461.3399P 2016MNRAS.461.3399P);
P17 = Petigura et al. (2017, J/AJ/154/107);
PC = Planet Candidate;
pCO = potential CO;
PDC = PDC lightcurves (Smith et al. 2012PASP..124.1000S 2012PASP..124.1000S);
pFP = Potential False Positive;
pOE = potential OE;
pOOTMOD = potential OOTMOD;
Poor trap fit = Poor trapezoidal fit;
pSS = Potential Significant Secondary;
R17 = Rizzuto et al. (2017, J/AJ/154/224);
RFS = Recommend Further Scrutiny;
S16 = Schmitt et al. (2016AJ....151..159S 2016AJ....151..159S);
S17 = Shporer et al. (2017, J/ApJ/847/18);
SEC = Secondary eclipse. Target is probably an eclipsing binary;
SFF = SFF lightcurves (Vanderburg et al. 2014PASP..126..948V 2014PASP..126..948V);
SNR = Signal-to-noise Ratio;
SS = Significant Secondary. Target is an eclipsing binary;
Spec = Spectrum;
SSAp = Second star in aperture;
V16 = Vanderburg et al. (2016, J/ApJS/222/14);
pVDE = Potentially Very Deep Eclipse. Size of the transiting object
potentially large (>2 RJup);
pVSHAPE = Potential V shaped transit.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 13-Jun-2019