Data Columns in the Kepler Stellar Table

The following table lists all of the data columns in the Kepler Stellar table that can be returned through the Exoplanet Archive's Application Programming Interface (API).

These column definitions apply to all deliveries of the Kepler stellar table. There are similar documents for the Confirmed Planets, TCE, Kepler Names and KOI tables.

The stellar table contains parameters for all targets observed by Kepler for the purpose of finding transiting planets. The current stellar table matches the values used by the Kepler pipeline when fitting TCEs identified in the Q1-12, Q1-16, Q1-17 DR 24 and Q1-17 DR 25 data. See the Kepler Stellar documentation page for more information about each delivery.

Objects with KIC or KepID numbers over 100,000,000 are custom apertures. Please note that although stellar values may be listed here as these objects were processed through the Kepler pipeline, not all of these objects are stars. More information on custom apertures is available in section 2.2.1 of the archive manual.

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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.

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Stellar Columns

Database Column Name Table Label Description Uncertainties Column
(positive +)
(negative -)
Displayed String Name
st_delivname† Delivery Name The stellar table delivery name from the Kepler Project.    
kepid† KepID (KIC number) Target identification number, as listed in the Kepler Input Catalog (KIC). The KIC was derived from a ground-based 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.    
tm_designation† 2MASS designation 2MASS designation    
ra† RA (deg) KIC Right Ascension    
dec† Dec (deg) KIC Declination    
kepmag Kepler-band (mag)† Kepler-band magnitude    
teff† Stellar Effective Temperature (Kelvin) The photospheric temperature of the star. teff_err1, teff_err2 teff_str
logg† Stellar Surface Gravity (log10(cm s-2)) The base-10 logarithm of the acceleration due to gravity at the surface of the star. logg_err1, logg_err2 logg_str
feh† Stellar Metallicity The base-10 logarithm of the Fe to H ratio at the surface of the star, normalized by the solar Fe to H ratio. feh_err1, feh_err2 feh_str
teff_prov† Effective Temperature Provenance A flag describing the source of the stellar effective temperature, surface gravity and metallicity.
  • KIC = the parameters are extracted from the Kepler Input Catalog (Brown et al. 2011). Uncertainties of Teff = 200 K, log(g) = 0.3 dex and [Fe/H] = 0.4.

  • J-K = the star is unclassified in the KIC, J-K has been used to estimate temperature. The host star is assumed to be on the ZAMS with corresponding log(g) based on the Schmidt-Kaler relation.

  • Pinsonneault = uses a revised Teff scale from Pinsonneault et al. (2012) with [Fe/H] fixed at -0.2. The quantity log(g) is taken from the KIC. Values are then revised by fitting to Yonsei-Yale stellar evolution models (Yi et al. 2001).

  • SPE = Spectroscopy

  • PHO = Photometry

  • TRA = Transits or Eclipsing Binaries

  • AST = Asteroseismology

  • Solar = No physical parameters are known for this object and so the pipeline used Solar values. These values were used directly without fitting.

If the letter code is trailed by a number, the number corresponds to a specific paper. That list is available here.

   
logg_prov† Surface Gravity Provenance
feh_prov† Metallicity Provenance
radius† Stellar Radius (solar radii) The photospheric radius of the star. radius_err1, radius_err2 radius_str
mass† Stellar Mass (solar mass) The mass of the star. mass_err1, mass_err2 mass_str
dens† Stellar Density (gm/cm**3) The density of the star. dens_err1, dens_err2 dens_str
prov_sec† Provenance of Secondary Stellar Parameters The internal parameters (R, M, rho) codes:
  • DSEP = Based on Dartmouth Stellar Evolution Program. DSEP given without a reference number corresponds to values derived with the model grid presented in Huber et al. 2013.

  • MULT = Based on multiple evolutionary tracks/isochrones, including DSEP

If the letter code is trailed by a number, the number corresponds to a specific paper. That list is available here.

   
dist Distance (pc) Distance to the star in units of parsecs dist_err1, dist_err2 dist_str
av Av Extinction (mag) Absorption and scattering of light in the V-band due to dust and gas in the line of sight. av_err1, av_err2 av_str
limbdark_coeff1 Limb Darkening Coefficient 1 These report values for the four-parameter, non-linear model of Claret & Bloemen (2011) assuming the DR25 stellar parameters (Mathur et al. 2016).    
limbdark_coeff2 Limb Darkening Coefficient 2    
limbdark_coeff3 Limb Darkening Coefficient 3    
limbdark_coeff4 Limb Darkening Coefficient 4    
nconfp† Number of Associated Confirmed Planets Number of Confirmed Planets identified in a system.    
nkoi† Number of KOIs Number of Kepler Objects of Interest identified in a system.    
ntce† Number of TCEs Number of Kepler TCEs identified in a system.    
st_quarters† Quarterly data exists A string of 17 zeros and ones indicating which quarters have Kepler data (i.e., at least a target pixel file). The left-most bit represents quarter 1 and the quarters increase to the right. A target that has data for quarters 1, 5, 6, 7, 8, 14, and 16 will have the following string: 10001111000001010.    
st_vet_date† Date of Last Update Date of the last parameter update for this KepID    

Default column: These columns display in the interactive table when the table is first loaded, and when Reset Filters is clicked.



Occurrence Rate Columns

Database Column Name Table Label Description
dutycycle Duty Cycle The fraction of data cadences within the span of observations that contain valid data and contribute toward detection of transit signals. The values for Duty Cycle ranges from 0.0 and 1.0.
dutycycle_post Duty Cycle Post Planet Removal The duty cycle calculated after the transit search is complete and all transit signals have been removed from the light curve. This metric is useful in identifying targets where large amounts of data were removed as a result of multiple planet search iterations.
dataspan Data Span [days] The time elapsed in days between the first and last cadences containing valid data.
dataspan_post Data Span Post Planet Removal [days] The data span calculated after the transit search is complete and all transit signals have been removed from the light curve. This metric is useful in identifying targets where large amounts of data were removed as a result of multiple planet search iterations.
mesthres01p5 Multiple Event Statistic (MES) threshold for a searched transit duration of 1.5 hours

The Multiple Event Statistic (MES) threshold reports the transit-signal significance level achieved by the transiting planet search (TPS) module.

There is one entry for each of the 14 transit durations (1.5, 2.0, 2.5, 3.0, 3.5, 4.5, 5.0, 6.0, 7.5, 9.0, 10.5, 12.0, 12.5, 15.0 hr) explored by TPS in the transit search.

A value of 7.1 indicates that TPS reached the nominal search threshold significance, whereas a value above 7.1 indicates that TPS ended the search prematurely at the higher specified significance threshold.

mesthres02p0 MES threshold: 2.0 hours
mesthres02p5 MES threshold: 2.5 hours
mesthres03p0 MES threshold: 3.0 hours
mesthres03p5 MES threshold: 3.5 hours
mesthres04p5 MES threshold: 4.5 hours
mesthres05p0 MES threshold: 5.0 hours
mesthres06p0 MES threshold: 6.0 hours
mesthres07p5 MES threshold: 7.5 hours
mesthres09p0 MES threshold: 9.0 hours
mesthres10p5 MES threshold: 10.5 hours
mesthres12p0 MES threshold: 12.0 hours
mesthres12p5 MES threshold: 12.5 hours
mesthres15p0 MES threshold: 15.0 hours
rrmscdpp01p5 Robust RMS CDPP for a searched transit duration of 1.5 hours

The robust root-mean-square (RMS) combined differential photometric precision (CDPP) is an empirical estimate of the noise in the relative flux time series observations. TPS computes a non-stationary time series of CDPP, which sets the significance level of detected transit signals.

The 14 entries are the CDPP time series summary statistics for 14 transit durations (i.e., 1.5, 2.0, 2.5, 3.0, 3.5, 4.5, 5.0, 6.0, 7.5, 9.0, 10.5, 12.0, 12.5, 15.0 hr) searched by TPS. These summary statistics are calculated in a robus fashion by excluding cadences de-weighted during the transit search and employing median and mean absolute deviation algorithms, rather than the less robust arithmetic mean and standard deviation. Specificaly, the standard definition of the root mean square deviation of a data set X is Xrms2 = Xmean2+Xstd2, where Xmean is the arithmetic mean of X and Xstd is the standard deviation of X. For the robust version, the arithmetic mean is replaced with the median and the standard deviation is replaced with the mean absolute deviation (mad) scaled to approximate the standard deviation, so that (Xrobust_rms)2 = (Xmedian)2 + (1.4826*Xmad)2.

rrmscdpp02p0 Robust RMS CDPP: 2.0 hours
rrmscdpp02p5 Robust RMS CDPP: 2.5 hours
rrmscdpp03p0 Robust RMS CDPP: 3.0 hours
rrmscdpp03p5 Robust RMS CDPP: 3.5 hours
rrmscdpp04p5 Robust RMS CDPP: 4.5 hours
rrmscdpp05p0 Robust RMS CDPP: 5.0 hours
rrmscdpp06p0 Robust RMS CDPP: 6.0 hours
rrmscdpp07p5 Robust RMS CDPP: 7.5 hours
rrmscdpp09p0 Robust RMS CDPP: 9.0 hours
rrmscdpp10p5 Robust RMS CDPP: 10.5 hours
rrmscdpp12p0 Robust RMS CDPP: 12.0 hours
rrmscdpp12p5 Robust RMS CDPP: 12.5 hours
rrmscdpp15p0 Robust RMS CDPP: 15.0 hours
cdppslplong rmsCDPP Slope for Long Transit Durations

The rmsCDPP slope for long transit durations is a linear fit to the log10(transit duration) versus log10(rmsCDPP) values for the six longest transit durations (e.g. 7.5, 9.0, 10.5, 12.0, 12.5, 15.0 hr).

Note: For white Gaussian noise, the rmsCDPP is expected to decrease with increasing transit duration because the noise decreases as the square-root of the number of in-transit cadences. However, targets with astrophysical noise or non-uniform power spectral densities can have rmsCDPP values that actually increase with increasing transit duration. Hence, this rmsCDPP slope serves as an indiator of non-white Gaussian noise behavior on the longest timescales searched. Monte-Carlo transit injection and recovery tests of the Kepler pipeline reveal that targets with large values of this rmsCDPP slope have suppressed transit recovery relative to targets with nominal rmsCDPP slopes.

cdppslpshrt rmsCDPP Slope for Short Transit Duration See the definition of of rmsCDPP slope for long transit duration. This metric is determined by fitting the slope of the second to sixth shortest transit durations (e.g. 2.0, 2.5, 3.0, 3.5, 4.5 hr) in order to characterize the noise on short timescales. This fit differs from the long transit duration slope in that it is performed in a semi-log space (e.g. log10(transit duration) versus rmsCDPP).
timeout01p5 Timeout Indicator for a searched transit duration of 1.5 hours The timeout indicators report whether the TPS planet search completed normally for the 14 transit durations. The searches in the TPS proceed from the longest transit duration to the shortest. The searches at individual durations end when their allocated share of resources is consumed and the entire search process ends when an overall timeout is reached.

Timeout indicator values:

  • 0 (zero) = the search ended normally after reaching its nominal significance threshold of 7.1;
  • 1 = the search ended prematurely, before the 7.1 significance threshold was achieved;
  • 2 = no transit search was attempted.
timeout02p0 Timeout Indicator: 2.0 hours
timeout02p5 Timeout Indicator: 2.5 hours
timeout03p0 Timeout Indicator: 3.0 hours
timeout03p5 Timeout Indicator: 3.5 hours
timeout04p5 Timeout Indicator: 4.5 hours
timeout05p0 Timeout Indicator: 5.0 hours
timeout06p0 Timeout Indicator: 6.0 hours
timeout07p5 Timeout Indicator: 7.5 hours
timeout09p0 Timeout Indicator: 9.0 hours
timeout10p5 Timeout Indicator: 10.5 hours
timeout12p0 Timeout Indicator: 12.0 hours
timeout12p5 Timeout Indicator: 12.5 hours
timeout15p0 Timeout Indicator: 15.0 hours
timeoutsumry Timeout Indicator Summary This is a binary flag where a value of 1 indicates that all 14 transit durations were searched down to the 7.1 significance threshold with no timeout issues, and a value of 0 (zero) indicates that at least one of the transit durations did not achieve a search down to the 7.1 significance threshold.

Other Stellar Columns

Database Column Name Table Label and Units Description Uncertainties Column
(positive +)
(negative -)
Displayed String Name
jmag J-band (2MASS) (mag) Brightness of the star as measured using the J (2MASS) band in units of magnitude. Uncertainty values larger than 8 indicate that a reliable estimate of the photometric error could not be determined. jmag_err jmag_str
hmag H-band (2MASS) (mag) Brightness of the star as measured using the H (2MASS) band in units of magnitude. Uncertainty values larger than 8 indicate that a reliable estimate of the photometric error could not be determined. hmag_err hmag_str
kmag K-band (2MASS) (mag) Brightness of the star as measured using the K (2MASS) band in units of magnitude. Uncertainty values larger than 8 indicate that a reliable estimate of the photometric error could not be determined. kmag_err kmag_str

Default column: These columns display in the interactive table when the table is first loaded, and when Reset Filters is clicked.



Columns Expected In Future Releases

The following parameters currently have no data, but will be populated in future releases. Until then, they will not be available through our services.

Database Column Name Displayed String Name Table Label and Units Description Uncertainties Column
(positive +)
(negative -)
age age_str Age (Gigayears) The age of the star age_err1, age_err2
plx plx_str Parallax (mas) Parallax plx_err1, plx_err2
pmtot pmtot_str Total Proper Motion (mas/yr) Total Proper Motion pmtot_err1, pmtot_err2
pmra pmra_str RA Proper Motion (mas/yr) Right Ascension Proper Motion pmra_err1, pmra_err2
pmdec pmdec_str dec Proper Motion (mas/yr) Declination Proper Motion pmdec_err1, pmdec_err2

Last updated: 22 March 2017