The following tables list all of the data columns in the Kepler TCE tables that can be returned through the Exoplanet Archive's Application Programming Interface (API) and used in the TCE interactive table. A ThresholdCrossing Event (TCE) is a sequence of transitlike features in the flux time series of a given target that resembles the signature of a transiting planet to a sufficient degree that the target is passed on for further analysis. For more information, see the TCE release notes.
There are similar documents for the Confirmed Planets table and the Kepler Planetary Candidates table.
Additional Links:
Questions about the structure and use of this table in the archive format should be submitted through the Exoplanet Archive's Helpdesk. Questions about the content descriptions should be sent to the Kepler Science Center.
Skip to a section:
Database Column Name  Table Label  Description 

kepid†  KepID or Kepler Identification  Target identification number, as listed in the Kepler Input Catalog (KIC). The KIC was derived from a groundbased imaging survey of the Kepler field conducted prior to launch. The survey's purpose was to identify stars for the Kepler exoplanet survey by magnitude and color. The full catalog of 13 million sources can be searched at the MAST archive. The subset of 4 million targets found upon the Kepler CCDs can be searched via the Kepler Target Search form. The Kepler ID is unique to a target and there is only one Kepler ID per target. 
tce_plnt_num†  Planet Number  Planet Number 
tce_rogue_flag†  Rogue Flag  This flag addresses a bug in DR25 and earlier versions of TPS, which inadvertently allowed a subset of signals that fail the "threetransit weight check" (see Section 2 of the DR25 window function documentation, KSCI19101) to become TCEs. The intent of the TPS algorithm was to fail signals that fail the "threetransit weight check." In order to enforce this intended criterion and create valid TCEs in a uniform manner, we have flagged 1498 of the 34032 TCEs identified in the DR25 pipeline run (Twicken et al. 2016) as "rogue" (or unintended) detections (i.e., tce_rogue_flag=1). These rogue TCEs are excluded from all subsequent analyses, so only the TCEs uniformly meeting the intended detection criteria (i.e., tce_rogue_flag = 0) are considered for inclusion in the DR25 KOI activity table and reflected in the DR25 occurrence rate products. 
tce_delivname  Delivery Name  The TCE delivery name from the Kepler project. Possible values are: q1_q12_tce, q1_q16_tce, q1_q17_dr24_tce, and q1_q17_dr25_tce 
rowupdate  Date of Last Update  Date of last update for this TCE 
tce_datalink_dvs  Link to DV Summary 
This is the relative path for the data validation summary;
use it when retrieving individual reports through the archive's
application programming interface with wget.
You must append the following URL to the file name in your
wget query:https://exoplanetarchive.ipac.caltech.edu/data/KeplerData/ 
tce_datalink_dvr  Link to DV Report 
This is the relative path for the data validation report;
use it when retrieving individual reports through the archive's
application programming interface with wget.
You must append the following URL to the file name in your wget query:https://exoplanetarchive.ipac.caltech.edu/data/KeplerData/ 
Transit parameters delivered by the Kepler Project are typically bestfit parameters produced by a MandelAgol (2002) fit to a multiquarter Kepler light curve, assuming a linear orbital ephemeris. Some of the parameters listed below are fit directly, other are derived from the bestfit parameters. Limb darkening coefficients are fixed and precalculated from host star properties. Orbital Period, Transit Epoch, PlanetStar Radius Ratio, PlanetStar Separation and mpact Parameter are the free parameters in the fit. Matrix covariances are adopted as errors to the fit parameters, they therefore ignore the effects of correlation between the fit parameters and are likely to be underestimates.
Database Column Name  Uncertainties Column (positive +) (negative ) 
Displayed String Name  Table Label  Description 

tce_period†  tce_period_err  tce_period_str  Orbital Period (days)  The interval between consecutive planetary transits. 
tce_time0bk†  tce_time0bk_err  tce_time0bk_str  Transit Epoch (BJD  2,545,833.0)  The time corresponding to the center of the first detected transit in Barycentric Julian Day (BJD) minus a constant offset of 2,454,833.0 days. The offset corresponds to 12:00 on Jan 1, 2009 UTC. 
tce_time0  tce_time0_err  tce_time0_str  Transit Epoch in BJD  The time corresponding to the center of the first detected transit in Barycentric Julian Day (BJD). 
tce_ror  tce_ror_err  tce_ror_str  PlanetStar Radius Ratio  The planet radius divided by the stellar radius. 
tce_dor  tce_dor_err  tce_dor_str  PlanetStar Separation  The distance between the planet and the star at midtransit divided by the stellar radius. For the case of zero orbital eccentricity, the distance at midtransit is the semimajor axis of the planetary orbit. 
tce_incl  tce_incl_err  tce_incl_str  Inclination (deg)  The angle between the plane of the sky (perpendicular to the line of sight) and the orbital plane of the planet candidate. 
tce_impact†  tce_impact_err  tce_impact_str  Impact Parameter  The skyprojected distance between the center of the stellar disc and the center of the planet disc at conjunction, normalized by the stellar radius. 
tce_duration†  tce_duration_err  tce_duration_str  Transit Duration (hrs)  The duration of the observed transits. Duration is measured from first contact between the planet and star until last contact. Contact times are typically computed from a bestfit model produced by a MandelAgol (2002) model fit to a multiquarter Kepler light curve, assuming a linear orbital ephemeris. 
tce_ingress  tce_ingress_err  tce_ingress_str  Ingress Duration (hrs)  The time between first and second contact of the planetary transit. Contact times are typically computed from a bestfit model produced by a MandelAgol (2002) model fit to a multiquarter Kepler light curve, assuming a linear orbital ephemeris. 
tce_depth†  tce_depth_err  tce_depth_str  Transit Depth (ppm)  The fraction of stellar flux lost at the minimum of the planetary transit. Transit depths are typically computed from a bestfit model produced by a MandelAgol (2002) model fit to a multiquarter Kepler light curve, assuming a linear orbital ephemeris. 
tce_eccen  tce_eccen_err  tce_eccen_str  Eccentricity  Eccentricity Value 
tce_longp  tce_longp_err  tce_longp_str  Long. of Periastron (deg)  Longitude of Periastron 
tce_limbdark_mod  Limb Darkening Model Name  A reference to the limb darkening model used to calculate stellar limb darkening coefficients.  
tce_ldm_coeff1, tce_ldm_coeff2, tce_ldm_coeff3, tce_ldm_coeff4  Limb Darkening Coefficients  Up to four coefficients (a_{1}, a_{2}, a_{3}, a_{4}) that define stellar limb darkening (e.g., Claret 2000). Limb darkening is the variation of specific intensity of the star as a function of μ = cos(θ). θ is the angle between the lineofsight of an observer and a line perpendicular to the stellar surface at an observed point. Coefficients are dependent upon stellar temperature, surface gravity and metallicity. Adopted coefficients are required input for MandelAgol (2002) fits and are extracted from archived tables (e.g., Claret and Bloemen 2011). Limb darkening coefficients remain fixed during fit minimization. Note that the dependence of limb darkening coefficients upon stellar parameters implies that planet radius does not scale linearly with stellar radius. If new stellar parameters are adopted, the mostcorrect approach is to refit the transit with new limbdarkening coefficients in order to remeasure planet size.  
tce_num_transits  Number of Transits  The number of expected transits or partiallyobserved transits associated with the planet candidate occurring within the searched light curve. This does not include transits that fall completely within data gaps.  
tce_trans_mod  Transit Model  A reference to the transit model used to fit the data (e.g., MandelAgol 2002).  
tce_full_conv  Full Convergence Flag  True or false. The model convergence indicates whether the fit converged to a solution. True indicates the fit was successful.  
tce_model_snr†  Transit SignaltoNoise (SNR)  Transit depth normalized by the mean uncertainty in the flux during the transits.  
tce_model_chisq  ChiSquare  The goodness of the transit fit to the data. Within the TCE table this quantity is the χ^{2} statistic. Within the KOI table this quantity is the reducedχ^{2} statistic, e.g., divided by the number of degrees of freedom in the fit.  
tce_model_dof  Degrees of Freedom  The number of degrees of freedom used when fitting the transit model to the data.  
tce_robstat  Robust Statistic  This statistic measures the significance of transit depth variations among the events that contribute to the potential TCE. In cases where the transit depths are consistent across all events, the robust statistic will equal the multiple event statistic (MES). The robust statistic will be less than the MES when the potential TCE consists of an inconsistent set of transit depths. As a result, the robust statistic is used by the pipeline to remove potential TCEs with significant transit depth variations, such as a single deep systematic event combined with numerous shallow events. A value significantly below the value of the MES indicates the TCE is made of inconsistent transit depths. The exact formulation of the robust statistic is found in Appendix A of Tenenbaum et al. (2013, ApJS, 206, 5).  
tce_dof1  Degrees of Freedom 1  The degrees of freedom associated with the first chisquare discriminator. It is used along with Chi Square 1 to remove likely falsepositives from the TCE list. For more information on how this value is used to remove falsepositives, see Appendix B of Tenenbaum et al. (2013, ApJS, 206, 5), and in more detail in Seader et al. (2013, ApJS, 206, 25).  
tce_dof2  Degrees of Freedom 2  The degrees of freedom associated with the second chisquare discriminator. It is used along with Chi Square 2 to remove likely falsepositives from the TCE list. For more information on how this value is used to remove falsepositives, see Appendix B of Tenenbaum et al. (2013, ApJS, 206, 5), and in more detail in Seader et al. (2013, ApJS, 206, 25).  
tce_chisq1  Chi Square 1  The first chisquare discriminator is used along with the associated degrees of freedom and MES to remove likely falsepositives from the TCE list. This statistic compares the single event statistic in the wavelet domain to what is expected given the noise. If the data match the model and the noise behaves as expected, this statistic should equal the degrees of freedom. Larger values indicate a poor match to the model given the estimate of the noise. The exact formulation of this statistic is described in Appendix B, equation B8, of Tenenbaum et al. (2013, ApJS, 206, 5) and in more detail in Seader et al. (2013, ApJS, 206, 25).  
tce_chisq2  Chi Square 2  The second chisquare discriminator used along with the associated degrees of freedom and MES to remove likely falsepositives from the TCE list. This statistic compares the measured temporal contributions to the multiple event statistic to what is expected. If the data matches the model and the noise behaves as expected, this statistic should equal the degrees of freedom. Larger values indicate a poor match to the model given the estimate of the noise. The exact formulation of this statistic is described in Appendix B, equation B13, of Tenenbaum et al. (2013, ApJS, 206, 5)) and in more detail in Seader et al. (2013, ApJS, 206, 25).  
tce_chisqgofdof  ChiSquare GOF DOF  The degrees of freedom for the chisquare goodness of fit measurement (see Seader et al. 2015, Appendix B).  
tce_chisqgof  ChiSquare GOF  The chisquare goodness of fit measures the difference between the amplitude of the detected signal in TPS and the signaltonoise ratio of the transit fit in DV (see Seader et al. 2015, Appendix B). 
Scaled planetary parameters combine the dimensionless fit parameters with physical stellar parameters to produce planet characteristics in physical units.
Database Column Name  Uncertainties Column (positive +) (negative ) 
Displayed String Name  Table Label  Description 

tce_prad†  tce_prad_err  tce_prad_str  Planetary Radius (Earth radii)  The radius of the planet. Planetary radius is the product of the planet star radius ratio and the stellar radius. 
tce_sma  tce_sma_err  tce_sma_str  Orbit SemiMajor Axis (AU)  Half of the long axis of the ellipse defining a planet's orbit. For a circular orbit this is the planetstar separation. The semimajor axis is derived based on Kepler's third law, i.e., utilizing the orbital period and stellar mass, not scaling the planetstar separation by the stellar radius. 
tce_eqt†  tce_eqt_err  tce_eqt_str  Equilibrium Temperature (K)  Approximation for the temperature of the planet. The calculation of equilibrium temperature assumes i) thermodynamic equilibrium between the incident stellar flux and the radiated heat from the planet, ii) a Bond albedo (the fraction of total power incident upon the planet scattered back into space) of 0.3, iii)that the planet and star are blackbodies, and iv) that the heat is evenly distributed between the day and night sides of the planet. 
tce_insol†  tce_insol_err  tce_insol_str  Insolation Flux  The insolation flux derived from the transiting planet model fit for the TCE relative to the Solar flux received at the top of Earth’s atmosphere. The theoretical habitable zone of a star is commonly given as a range of insolation fluxes. 
Bestfit planetary transit parameters are typically normalized to the size of the host star. Physical planet parameters may be derived by scaling to the star's size and temperature. Transit parameters also depend weakly upon the limb darkening coefficients which are derived from the stellar parameters (e.g., Claret and Bloemen 2011). Stellar effective temperature, surface gravity, metallicity, radius, mass, and age should comprise a consistent set. Associated error estimates are 1σ uncertainties.
Database Column Name  Uncertainties Column (positive +) (negative ) 
Displayed String Name  Table Label  Description 

tce_nkoi  Number of Associated KOIs  The total number of TCEs detected on this target by DV during the specified run. This should not be confused with the planet number, which is used to denote different TCEs on the same target.  
tce_ioflag  Interesting Object Flag  This flag indicates the object is on the "list of interesting objects" posted by the Kepler project for the Q117 DR24 transit search.  
tce_quarters  Quarters Passed 
A string of seventeen zeroes and ones indicating which
quarters contain data that were passed to Transit Planet
Search (TPS). The leftmost bit represents quarter 1 and
the quarters increase to the right. A target with data
in quarters 1, 3, 5, 7, 8, 13, 15, 17 will have the
following string: 10101011000010101 . 

tce_steff†  tce_steff_err  tce_steff_str  Stellar Effective Temperature (K)  The photospheric temperature of the star. 
tce_slogg†  tce_slogg_err  tce_slogg_str  Stellar Surface Gravity (log_{10}(cm s^{2})  The base10 logarithm of the acceleration due to gravity at the surface of the star. 
tce_smet  tce_smet_err  tce_smet_str  Stellar Metallicity (dex)  The base10 logarithm of the Fe to H ratio at the surface of the star, normalized by the solar Fe to H ratio. 
tce_sradius†  tce_sradius_err  tce_sradius_str  Stellar Radius (Solar radii)  The photospheric radius of the star. 
tce_steff_prov  Stellar Effective Temperature Provenance 
A flag describing the source of the stellar effective temperature, surface gravity and metallicity.


tce_slogg_prov  Stellar Surface Gravity Provenance  
tce_smet_prov  Stellar Metallicity Provenance  
tce_sradius_prov  Stellar Radius Provenance 
The internal parameters (R, M, rho) codes:
If the letter code is trailed by a number, the number corresponds to a specific paper. 
A trapezoidal model is fit to a quarterstitched, harmonics removed, detrended light curve at the TCE's period. Cadences during transit are given zero weight during the detrending. The fitted parameters for the trapezoidal fit are epoch (BKJD), transit duration (hours), ingress time (hours), and transit depth (ppm). The full convergence parameter is set to true when the fit is successful (see Garcia, D., Computational Statistics & Data Analysis, 2010, 54, 1167 for further details).
Database Column Name  Uncertainties Column (positive +) (negative ) 
Displayed String Name  Table Label  Description 

tcet_period  tcet_period_err  tcet_period_str  Orbital Period  Orbital period in days for the trapezoidal model fit to the detrended flux time series associated with the TCE. The orbital period is fixed to the value found by the transiting planet search for the given TCE. 
tcet_time0bk  tcet_time0bk_err  tcet_time0bk_str  Transit Epoch [BKJD]  Zeropoint for the trapezoidal model fit to the detrended flux time series in Kepler BJD (BJD – 2,454,833.0) for the given TCE. 
tcet_time0  tcet_time0_err  tcet_time0_str  Transit Epoch [BJD]  Zeropoint for the trapezoidal model fit to the detrended flux time series in BJD for the given TCE. 
tcet_duration  tcet_duration_err  tcet_duration_str  Transit Duration  Transit duration in hours for the trapezoidal model fit to the detrended flux time series for the given TCE. 
tcet_ingress  tcet_ingress_err  tcet_ingress_str  Transit Ingress Duration  Transit ingress time in hours for the trapezoidal model fit to the detrended flux time series for the given TCE. 
tcet_depth  tcet_depth_err  tcet_depth_str  Transit Depth  Transit depth in ppm for the trapezoidal model fit to the detrended flux time series for the given TCE. 
tcet_full_conv  Trap Fit Convergence  The model convergence indicates whether the trapezoidal fit converged to a solution. True indicates the fit was successful.  
tcet_model_dof  Trap Fit Degrees of Freedom  The number of degrees of freedom used when fitting the trapezoidal model to the data.  
tcet_model_chisq  Trap Fit model ChiSquare  The goodness of the trapezoidal fit to the data. This quantity is the chisquared statistic. 
Afer finding a transit signature (or thresholdcrossing event, TCE), the pipeline searches for a secondary eclipse and provides statistics to determine ig the identified event is real. This is done by removing the primary transit signature from the light curve and recalculating the multipleevent statistic (MES) for the same period and duration. The phase where the resulting MES time series reaches maximum is regarded as the "significant secondary" event and used to evaluate the results of this test. Occasionally, the largest MES event is associated with a feature in the light curve that is not a secondary event, such as the edge of the primary or another planet in the system.
Database Column Name  Table Label  Description 

wst_robstat  Weak Secondary Robust Statistic  The robust statistic computed for the possible secondary event identified at the maxMES Phase. This statistic measures the significance of the transit signal after suppressing the contribution of statistical outlying observations. If its value is small, the detected secondary signal may not be an astrophysical eclipse. 
wst_depth  Weak Secondary Depth  The fitted depth, in parts per million, of the most significant secondary transit signature. 
tce_mesmedian  Weak Secondary Median MES  Median value over all phases of all MES values computed at the period and pulse duration of the TCE in the absence of the primary transit event. If significantly different than zero, it may indicate that there are systematic features in the light curve at the TCE’s period and duration. 
tce_mesmad  Weak Secondary MADMES  Median absolute deviation over all phases of the multiple event statistic computed at the period and pulse duration of the TCE in the absence of the primary transit event. If the MADMES is comparable to the identified secondary’s maxMES, then the secondary may not be a significant detection. 
tce_maxmes  Weak Secondary max MES  Statistic (MES), similar to SNR, of the most significant secondary at the same period and duration as the primary. 
tce_minmes  Weak Secondary min MES  Minimum multipleevent statistic over all phases computed at the period and pulse duration of the TCE in the absence of the primary transit events. The minimum MES is the significance of the largest positive excursion associated with the TCE, which, if significant, may indicate there are systematic features in the light curve at the TCE’s period and duration. 
tce_maxmesd  Weak Secondary max MES Phase  Phase, in barycentric days offset by 2454833, associated with the largest detected secondary event. The phase zeropoint is the center of the original TCE’s primary transit. 
tce_minmesd  Weak Secondary min MES Phase  Phase in days associated with the minimum multipleevent statistic for the largest positive excursion associated with the TCE. The phase zeropoint is the center of the original TCE’s primary transit. 
The Transiting Planet Search (TPS) module of the Kepler data analysis pipeline performs a detection test for planet transits in the multiquarter, gapfilled flux time series. The TPS module detrends each quarterly PDC light curve to remove edge effects around data gaps and then combines the data segments together, filling gaps with interpolated data so as to condition the flux time series for a matched filter. The module applies an adaptive, waveletbased matched filter (Jenkins 2002, Jenkins et al. 2010 and Tenenbaum et al. (2012)) to perform a joint characterization of observation noise and detection of transitlike features in the light curve.
The TPS module estimates the Power Spectral Density of the flux time series as a function in time. This provides coefficients for a whitening filter to accommodate nonstationary, nonwhite noise and yields Single Event Statistic (SES) time series components. These can be interpreted as measurements of the statistical significance of the presence of a transit of trial duration at each point in the time series.
Single Event Statistics are folded at each trial orbital period and the maximum Multiple Event Statistic (MES) is obtained over all trial periods and phases. The MES estimates the signal to noise ratio of the putative transitlike sequence against the measurement noise. The MES threshold for defining the sample of ThresholdCrossing Events (TCEs) is provided within the Release Notes. For reference, a lower MES threshold of 7.1σ limits the number of false positives in the TCE sample due to statistical random noise to less than 1 over the primary mission (Jenkins, Caldwell and Borucki 2002).
Database Column Name  Table Label  Description 

tce_max_sngle_ev  Single Event Statistic  The maximum calculated value of the SES. Maximum SES statistics for different TCEs from the same target differ because the most significant TCE is removed from the time series before repeating the test for further, weaker transit signals. 
tce_max_mult_ev  Multiple Event Statistic (MES)  The maximum calculated value of the MES. TCEs that meet the maximum MES threshold criterion and other criteria listed in the TCE release notes are delivered to the Data Validation (DV) module of the Kepler data analysis pipeline for transit characterization and the calculation of statistics required for disposition. A TCE exceeding the maximum MES threshold are removed from the timeseries data and the SES and MES statistics recalculated. If a second TCE exceeds the maximum MES threshold then it is also propagated through the DV module and the cycle is iterated until no more events exceed the criteria. Candidate multiplanet systems are thus found this way. Users of the TCE table can exploit the maximum MES statistic to help filter and sort samples of TCEs for the purposes of discerning the event quality, determining the likelihood of planet candidacy, or assessing the risks of observational followup. 
tce_minmes  Minimum MES  
tce_mesmad  Median Absolute Deviation (MAD) MES  
tce_bin_oedp_sig  OddEven Depth Comparison Statistic  A transit model is fit independently to the evennumbered transits and the oddnumbered transits. The depth of the fit to evennumbered transits is compared to that of the oddnumbered transits. A statistically significant difference in the transit depths is an indication of a planetary candidate false positive, due either to a background binary contaminant in the light curve or a binary star system displaying a grazing eclipse. The oddeven depth statistic is a number by which the depths of the odd transit and even transit fits deviate. The larger the statistic, the more likely the event is an astrophysical false positive. The oddeven diagnostic is only useful for identifying circular or nearcircular binary stars. The TCE table provides the statistic by a percentage likelihood of depth mismatch, whereas the KOI table provides the statistic in terms of the number of σ deviating from equal depth. 
tce_rmesmad  Calculated Ratio MES over MAD MES  
tce_rsnrmes  Calculated Ratio SNR over MES  
tce_rminmes  Calculated Ratio Min. MES over MES 
Database Column Name  Table Label  Description 

tce_albedo  Secondary Geometric Albedo  The geometric albedo of a planet that would produce the observed secondary depth when occulted by the host star, given the planet’s radius and semimajor axis, assuming all light from the planet is due to reflection. The geometric albedo is given by D * (a^2) / (Rp^2), where D is transit depth, a is semimajor axis, and Rp is planet radius. Values greater than 1 indicate the TCE is caused by a selfluminous companion (i.e., the system is an eclipsing binary). 
tce_ptemp  Planet Effective Temperature  The effective temperature of a planet that is consistent with the observed secondary depth when occulted by the host star. This is calculated using the planet’s and star’s radii and the system’s semimajor axis, assuming all light from the planet is due to thermal emission. The planetary effective temperature is given by (D^1/4) * Teff / (Rp/R*)^1/2, where Rp/R* is tce_ror, Teff is tce_steff, and D is tce_depth. 
tce_albedo_stat  Albedo Comparison Statistic  The difference between the geometric albedo associated with the most significant secondary event and 1.0. The value is given in units of standard deviations. The TCE is likely to be a false positive if the maximum secondary multipleevent statistic is above the transit detection threshold and the albedo comparison statistic is statistically significant. 
tce_ptemp_stat  Effective Temperature Comparison Statistic  The difference between the planet effective temperature associated with the most significant secondary event and the planet equilibrium temperature. The value is given in units of standard deviations. The TCE is likely to be a false positive if the secondary maximum multiple event statistic is above the transit detection threshold and the temperature comparison statistic is statistically significant. 
The autovetter is a machinelearning classifier that dispositions TCEs into the three classes: PC (Planet Candidate), AFP (Astrophysical False Positive) and NTP (NonTransiting Phenomenon). It uses the Random Forest, a decision treebased machine learning technique, and also provides a Bayesian determination of the posterior probability for the TCE to be in each of the three classes. For TCEs classified as PCs, the posterior probability to be in the class PC is a measure of our confidence in the classification.
The autovetter "learns" heuristics developed by TCERT as well as other diagnostics, then applies them uniformly and consistently to classify the TCEs and produces a catalog of planet candidates.
For more detail about the autovetter and its random forest underpinning, see Automatic Classification of Kepler Planetary Transit Candidates, McCauliff et al. 2015 ApJ 806, 6.
The autovetter requires two inputs:
The autovetter produces the following outputs for each TCE:
Database Column Name  Table Label  Description 

av_vf_pc  Autovetter Planet Candidate Vote Fraction [percent]  Vote fraction value for Planet Candidate class 
av_vf_pc_err  Autovetter Planet Candidate Vote Fraction Error [percent]  The error in the mean class vote fraction from a set of 10 random forest runs is the standard deviation in the class vote fraction divided by the square root of 10. 
av_vf_afp  Autovetter Astrophysical False Positive Vote Fraction [percent]  Vote fraction value for Astrophysical False Positive class 
av_vf_afp_err  Autovetter Astrophysical False Vote Fraction Error [percent]  The error in the mean class vote fraction from a set of 10 random forest runs is the standard deviation in the class vote fraction divided by the square root of 10. 
av_vf_ntp  Autovetter NonTransiting Phenomena Vote Fraction [percent]  Vote fraction value for NonTransiting Phenomena class 
av_vf_ntp_err  NonTransiting Phenomena Vote Fraction Error [percent]  The error in the mean class vote fraction from a set of 10 random forest runs is the standard deviation in the class vote fraction divided by the square root of 10. 
av_pp_pc  Autovetter Planet Candidate Posterior Probabilities [percent]  Posterior probabilities for Planet Candidate class. 
av_pp_afp  Autovetter Astrophysical False Positive Posterior Probabilities [percent]  Posterior probabilities for Astrophysical False Positive class. 
av_pp_ntp  Autovetter NonTransiting Phenomena Posterior Probabilities [percent]  Posterior probabilities for NonTransiting Phenomena class. 
av_training_set  Autovetter Training Set Label 
If the TCE was included in the training set, the training label
encodes what is believed to be the "true" classification,
and takes a value of either PC, AFP
or NTP. The TCEs in the UNKNOWN class sample are marked UNK. Training labels are given a value of NULL for TCEs not included in the training set. For more detail about how the training set is constructed, see Autovetter Planet Candidate Catalog for Q1Q17 Data Release 24 (KSCI19091). 
av_pred_class  Autovetter Predicted Classification  Predicted classifications, which are the "optimum MAP classifications." Values are either PC, AFP, or NTP. 
Database Column Name  Table Label  Description 

boot_fap  Bootstrap False Alarm Probability  The Probability of False Alarm (PFA) is defined to be the integral part of the distribution of the null detection statistic above the value of the detection statistic returned by the search. The probability density function of the null Multiple Event Statistic (MES) is estimated by a bootstrap algorithm. Nominally, the null MES is Gaussian distributed with zero mean and unit variance. In reality, however, due to imperfections in the whitening process, the distribution of the null MES deviates from this nominal distribution form. The PFA is then calculated from the corresponding cumulative distribution function of the null MES using the search threshold of 7.1 sigma. 
boot_mesthres  Bootstrap MES Threshold  The threshold required, given the distribution of the MES estimated from the bootstrap algorithm, to achieve the same PFA as using a 7.1 sigma threshold on a Gaussian distribution with zero mean and unit variance (~6.24e13). 
boot_mesmean  Bootstrap Mean of MES Distribution  The mean of the bestfit Gaussian distribution to the null MES distribution estimated by the bootstrap. 
boot_messtd  Bootstrap Standard Deviation of MES Distribution  The standard deviation of the bestfit Gaussian distribution to the null MES distribution estimated by the bootstrap. 
The ghost diagnostic determines whether a transit signature is likely the result of an optical ghost. If the core aperture correlation statistic is smaller than the halo aperture correlation statistic, then contamination by an optical ghost is likely.
Database Column Name  Table Label  Description 

tce_cap_stat  Ghost Core Aperture Statistic  This statistic measures the correlation between the transit model and the average flux per pixel in the core aperture minus the average flux per pixel in the halo aperture. The core aperture is the optimal photometric aperture associated with the target in each quarter. It is assumed that null correlation statistics are drawn from a standard normal distribution. 
tce_hap_stat  Ghost Halo Aperture Statistic  This statistic measures the correlation between the transit model and the average flux per pixel in the halo aperture. The halo aperture is an annulus surrounding the optimal photometric aperture associated with the target in each quarter. It is assumed that null correlation statistics are drawn from a standard normal distribution. 
A temperaturesensitive amplifier oscillation at >1 GHz on some channels can superimpose a Moiré pattern on the CCD readout by sampling the highfrequency oscillation at the 3MHz serialpixel clocking rate. Since the amplifier oscillation frequency drifts with the temperature of the electronic components by as much as 500 kHz/°C, the signal from a given pixel in a series of dark images has a time varying signature. This signature may be highly correlated with neighboring pixels and yet poorly correlated with slightly more distant pixels. When the oscillation frequency is a harmonic of the serial clocking frequency, the sampled high frequency oscillation produces an offset from the mean biaslevel in the image 10 to 100 rows wide across all CCD columns. As the high frequency drifts with temperature, the rows on the image where this shift occurs move up or down producing a Rolling Band Artifact (RBA). The signature of a rolling band is a timevarying displacement in trailing black spatial fit residual time series. Convolution of a square wave transit kernel with this time series produces a time series of detected transit depths. Normalizing by the uncertainty in detected transit depth produces a time series of detection statistics in sigma. DV reports significant RBAs that are correlated with the ephemeris of the TCE for the rows that makeup its optimal aperture.
Database Column Name  Table Label  Description 

tce_tb_tpdur  Test Pulse Duration  The pulse duration (in units of long cadences) used to report detected RBAs in the black residuals. The chosen transit duration is usually the one that is closest to the transit duration associated with the given TCE. 
tce_rb_tcount$i$  Transit Counts $i$ (where i=0,1,2,3,4)  The number of transits for the given TCE coincident with rolling band artifacts at a level indicated by the column name. The number of impacted transits are given for five different levels, they are 0: 01, 1: 12, 2: 23, 3:3 4, and 4: >=4. The severity levels are in units of sigma. The maximum severity level over all rows in the optimal aperture is reported as the severity for the target on each cadence. Transits are not counted at any severity level when they occur on cadences where the rolling band flags are undefined. The number of transits shown for a severity level of zero is reported on the onepage DV summaries as the parameter RollingBandfgt. 
Planetary transit false positives are commonly caused by light curve contamination from an eclipsing binary falling partially within the target aperture (i.e., the pixels used to collect and sum target flux). Two pixel analysis methods are used to identify such eclipsing binaries: fluxweighted centroiding, which measures how the center of light in the collected pixels changes during a transit, and PRFfit difference images, which localize the source of the transit signal. Both methods provide an estimate of the location of the source of the transit signal. When that source location is offset from the target star by more than 3σ, it is likely that the transit signal is due to a background source (note the caveats due to crowding described below). These analysis techniques use pixellevel data, available in the Target Pixel Files (TPFs). The resulting position measurements are compared with the Kepler Input Catalog (KIC) (Brown et al. 2011).
In fluxweighted centroid analysis, when more than one source is present within a pixel aperture, either fully or partially, then the combined center of light within the collected pixels will occur between the locations of the sources. When the flux from either the target or one of the nearby contaminants varies in a transit or eclipse, then the combined center of light within the aperture will move across the focal plane. This motion is called a centroid shift. The location of the varying source can often be inferred from the centroid shift. The size and direction of the centroid shift is measured using the fluxweighted (FW) mean, (e.g., the first moment of the pixel data). This mean is computed with every flux measurement (30minute long cadence), creating a time series of fluxweighted means. The centroid shift is measured by comparing portions of the fluxweighted mean time series that are OutOfTransit (OOT) with portions that are InTransit (IT). The fluxweighted shift of the IT mean from the OOT mean is given as Right Ascension and Declination shifts. The offset of the transiting source object from the OOT fluxweighted mean is computed by taking the product of the FW shift and the factor [1  1 / (fractional transit depth)]. The Right Ascension, α (J2000), and Declination, δ (J2000), of the transiting object calculated in this way are reported in the table. The α and δ offsets of the resulting source location from the KIC target star position are also reported. The uncertainties and significance of the FW shifts and offsets are provided but do not reflect systematics caused by crowding. The fluxweighted method can be very accurate when the target star is well isolated and the transit source is located (well) within the flux aperture associated with the target star.
The PRFfit difference image method uses three images: i) an average of OutOfTransit (OOT) Target Pixel File images from data that were obtained near but not during transit events, ii) an average of InTransit (IT) image Target Pixel File images that were collected during transit events, and iii) a Difference Image (DIFF) that is the difference between the OutOfTransit and InTransit average images. The difference image provides an image of the transit source (neglecting variability of field stars). The Pixel Response Function (PRF) is a convolution of the Kepler Point Spread Function model with a model of typical spacecraft pointing jitter, providing a system point spread function (Bryson et al. 2010). The PRF is fit separately to the OOT and DIFF images, providing a measured location of the target star (fit to the OOT image) and a measured location of the transit source (fit to the DIFF image). The offset of the transit source location from the target star is given in the table as Right Ascension and Declination offsets (Δα,Δδ) as well as magnitude (sky offset Δθ).
PRF offsets can only be computed on a perquarter basis. The single quarter (SQ) PRF offsets are combined by a weighted mean.
The target position measured by the PRF fit to the OOT images is vulnerable to crowding. Therefore an alternative PRF offset of the transit source (measured by the PRF fit to the DIFF image) from the KIC position of the target star is provided. Both the fluxweighted and PRFfit methods will have systematic errors due to crowding when other stars appear in the aperture's pixels, though these error are smaller for the PRFfit method compared to the fluxweighted method.
The associated error estimates are 1σ uncertainties.
Database Column Name  Uncertainties Column (positive +) (negative ) 
Displayed String Name  Table Label  Description 

tce_fwm_stat  FluxWeighted Offset Significance (percent)  Indicates whether there is a statistically significant fluxweighted offset between intransit and outoftransit images. 100% indicates there is no offset and there is confidence that the transit is on the target star. The accuracy of this calculation degrades when the transit source has significant flux that falls outside the photometric aperture + a halo of pixels around it.  
tce_fwm_sra  tce_fwm_sra_err  tce_fwm_sra_str  FW Source α(OOT) (hours)  The Right Ascension (J2000) of the location of the transiting object calculated from the fluxweighted centroids. This result does not reflect the systematics due to crowding which can introduce significant errors in the calculated position 
tce_fwm_sdec  tce_fwm_sdec_err  tce_fwm_sdec_str  FW Source δ(OOT) (degrees)  The Declination (J2000) of the location of the transiting object calculated from the fluxweighted centroids. This result does not reflect the systematics due to crowding which can introduce significant errors in the calculated position. 
tce_fwm_srao  tce_fwm_srao_err  tce_fwm_srao_str  FW Δα(OOT)(seconds (not arcseconds))  The RA (J2000) fluxweighted centroid shift. This is the RA of the intransit flux weighted centroid minus the RA of the outoftransit flux weighted centroid. 
tce_fwm_sdeco  tce_fwm_sdeco_err  tce_fwm_sdeco_str  FW Δδ(OOT)(arcseconds)  The Dec (J2000) fluxweighted centroid shift. This is the Dec of the intransit flux weighted centroid minus the Dec of the outoftransit flux weighted centroid. 
tce_fwm_prao  tce_fwm_prao_err  tce_fwm_prao_str  FW Source Δα(OOT) (seconds (not arcseconds))  The calculated Right Ascension offset of the transiting or eclipsing object from the KIC location of the target star. The accuracy of this calculation degrades when the transit source has significant flux that falls outside the photometric aperture + a halo of pixels around it. 
tce_fwm_pdeco  tce_fwm_pdeco_err  tce_fwm_pdeco_str  FW Source Δδ(OOT) (arcseconds)  The calculated Declination offset of the transiting or eclipsing object from the KIC location of the target star. The accuracy of this calculation degrades when the transit source has significant flux that falls outside the photometric aperture + a halo of pixels around it. 
tce_dicco_mra  tce_dicco_mra_err  PRF Δα_{SQ}(OOT) (arcseconds)  The angular offset in the RA (J2000) direction between the bestfit PRF centroids from the OutOfTransit image and the Difference Image by averaging the weighted singlequarter measurements. The outoftransit centroids are subtracted from the difference image centroids.  
tce_dicco_mdec  tce_dicco_mdec_err  tce_dicco_mdec_str  PRF Δδ_{SQ}(OOT) (arcseconds)  The angular offset in the Dec (J2000) direction between the bestfit PRF centroids from the OutOfTransit image and the Difference Image by averaging the weighted singlequarter measurements. The outoftransit centroids are subtracted from the difference image centroids. 
tce_dicco_msky  tce_dicco_msky_err  tce_dicco_msky_str  PRF Δθ_{SQ}(OOT) (arcseconds)  The angular offset on the plane of the sky between the bestfit PRF centroids from the OutOfTransit image and the Difference Image by averaging the weighted singlequarter measurements. The outoftransit centroids are subtracted from the difference image centroids. 
tce_dikco_mra  tce_dikco_mra_err  tce_dikco_mra_str  PRF Δα_{SQ}(KIC) (arcseconds)  The angular offset in the RA (J2000) direction between the bestfit PRF centroids from the difference image and the Kepler Input Catalog position by averaging the weighted singlequarter measurements. The KIC position is subtracted from the difference image centroids. 
tce_dikco_mdec  tce_dikco_mdec_err  tce_dikco_mdec_str  PRF Δδ_{SQ}(KIC) (arcseconds)  The angular offset in the Dec (J2000) direction between the bestfit PRF centroids from the difference image and the Kepler Input Catalog position by averaging the weighted singlequarter measurements. The KIC position is subtracted from the difference image centroids. 
tce_dikco_msky  tce_dikco_msky_err  tce_dikco_msky_str  PRF Δθ_{SQ}(KIC) (arcseconds)  The angular offset in the plane of the sky between the bestfit PRF centroids from the difference image and the Kepler Input Catalog position by averaging the weighted singlequarter measurements. The KIC position is subtracted from the difference image centroids. 
Last updated: 31 August 2017