Robovetter Minor Flags in the Kepler Objects of Interest Table

The koi_comment field provides in the KOI table provides descriptions of the reasons why an object's disposition has been given as false positive. In the DR 24 table (Coughlin et al. 2015) and DR 25 KOI table (Thompson et al. 2017, in prep), the comment field also displays the minor flags from the DR 24 Robovetter or DR 25 Robovetter.

While the major flags (Not Transit-Like, Stellar Eclipse, Centroid Offset, and Ephemeris Match Indicates Contamination) indicate broad false positive (FP) categories, minor flags indicate the results of each specific test performed by the Robovetter. All FP KOIs will have at least one minor flag set, but some minor flags are informational only and do not necessarily indicate the KOI is a FP. All applicable flags are listed in the comment field separated by "---". (See the koi_comment entry in the Kepler Candidate Data Definitions document for descriptions of the major flags.)

Note that the Robovetter is run on the entire set of Threshold Crossing Events (TCEs), and thus the test results refer to the TCEs instead of the KOIs. Coughlin (2017; KSCI-19105) provides a more detailed discussion of the products, conventions, and nomenclature used in these minor flag definitions.

Click to view the DR 24 KOI Robovetter Minor Flags

DR 25 KOI Robovetter Minor Flags

In alphabetical order, the DR 25 Robovetter minor flags are:

  • ALL_TRANS_CHASES: This flag is set when the per TCE Chases metric is above threshold. This indicates that the shapes of the individual transits are generally not reliable and the TCE is dispositioned as an FP with the not transit-like major flag set.
  • CENT_CROWDED: This flag is set as a warning that more than one potential stellar image was found in the difference image, and thus a reliable centroid measurement cannot be obtained.
  • CENT_FEW_DIFFS: Fewer than 3 difference images of sufficiently high SNR are available, and thus very few tests in the pipeline's centroid module are applicable to the TCE. If this flag is set in conjunction with the CENT_RESOLVED_OFFSET flag, it serves as a warning that the source of the transit may be on a star clearly resolved from the target.
  • CENT_FEW_MEAS: The PRF centroid fit used by the pipeline's centroid module does not always converge, even in high SNR difference images. This flag is set as a warning if centroid offsets are recorded for fewer than 3 high SNR difference images.
  • CENT_INVERT_DIFF: One or more difference images were inverted, meaning the difference image claims the star got brighter during transit. This is usually due to variability of the target star and suggests the difference image should not be trusted. When this flag is set, it is a warning that the TCE requires further scrutiny, but the TCE is not marked as an FP due to a centroid offset.
  • CENT_KIC_POS: This measured offset distance is relative to the star's recorded position in the Kepler Input Catalog (KIC), not the out of transit centroid. Both are useful, since the KIC position is less accurate in sparse fields, but more accurate in crowded fields. If this is the only flag set, there is no reason to believe a statistically significant centroid shift is present (Mullally 2017), since a catalog error is equally likely.
  • CENT_NOFITS: The transit was not fit by a model in DV and thus no difference images were created for use by the pipeline's centroid module, so this flag is set as a warning that the TCE cannot be evaluated. This flag is typically set for very deep transits due to eclipsing binaries.
  • CENT_RESOLVED_OFFSET: The TCE has a significant centroid offset because the transit occurs on a star that is spatially resolved from the target. The TCE is marked as an FP with the centroid offset flag set unless one of the other Centroid Robovetter flags is also set, casting doubt on the measurement.
  • CENT_SATURATED: The star is saturated, so the Robovetter's centroiding assumptions break down. This flag is set as a warning, indicating that the TCE cannot be reliably evaluated.
  • CENT_UNCERTAIN: The Centroid Robovetter (Mullally 2017) determined that the significance of the centroid offset cannot be measured to high enough precision, so this flag is set as a warning that the TCE cannot be confidently dispositioned as an FP. This is typically due to having only a very small number (i.e., 3 or 4) of offset measurements, all with low SNR.
  • CENT_UNRESOLVED_OFFSET: There is a statistically significant shift in the centroid during transit. This indicates the variability is not due to the target star. Thus, the TCE is dispositioned as an FP with the centroid offset major flag set, unless another Centroid Robovetter flag is also set, casting doubt on the measurement.
  • DEEP_V_SHAPED: The V-shape metric is above threshold. This metric uses the fitted DV radius ratio and impact parameter to determine whether the event is likely to be caused by a stellar eclipse. When the flag is set, the TCE is dispositioned as an FP with the stellar eclipse major flag set.
  • DEPTH_ODDEVEN_ALT: The TCE failed the odd-even depth test using the alternate detrending. This determines whether the difference in the depths of the odd and even transits is greater than the standard deviation of those depths. The transit-like TCE is marked as an FP with a stellar eclipse major flag set.
  • DEPTH_ODDEVEN_DV: The TCE failed the odd-even depth test using the DV detrending. This determines whether the difference in the depths of the odd and even transits is greater than the standard deviation of those depths. The transit-like TCE is marked as an FP with a stellar eclipse major flag set.
  • EPHEM_MATCH: The TCE has been identified as an FP due to an ephemeris match with a source that could plausibly induce the observed variability on the target. See the DR25 KOI Catalog paper (Thompson et al. 2017) for the contaminating source.
  • HALO_GHOST: The ghost diagnostic value is too high. This diagnostic measures the transit strength for the out- and in-aperture pixels and determines if the transit is localized on the target star, or if it is due to contamination from a distant source. The TCE is an FP and the centroid offset major flag is set.
  • HAS_SEC_TCE: Another TCE on the same target with a higher planet number has the same period as the current transit-like TCE, but a significantly different epoch. This indicates that the current TCE is an eclipsing binary with the other TCE representing the secondary eclipse. If the PLANET_OCCULT_DV and PLANET_OCCULT_ALT flags are not set, the TCE is dispositioned as an FP with a stellar eclipse major flag set.
  • INCONSISTENT_TRANS: The ratio of the maximum SES value to the MES value is above threshold and the TCE has a period greater than 90 days. This flag indicates that the TCE has only a few transits and the MES is dominated by a single large event. Thus, the TCE is dispositioned as an FP with the not transit-like major flag set.
  • INDIV_TRANS_(CHASES|MARSHALL|SKYE|ZUMA|TRACKER|RUBBLE): One or more of the individual transit metrics (Chases, Marshall, Skye, Zuma, Tracker, or Rubble) removed a transit causing the TCE's recalculated MES to drop below threshold, or the number of transits to drop below 3. The TCE is dispositioned as an FP with the not transit-like major flag set.
  • IS_SEC_TCE: The TCE is determined to have the same period, but a different epoch, as a previous transit-like TCE. This indicates that the current TCE corresponds to the secondary eclipse of an eclipsing binary (or a planet if the PLANET_OCCULT_DV or PLANET_OCCULT_ALT flags are set). Thus, the current TCE is dispositioned as an FP with both the not transit-like and stellar eclipse major flags set.
  • LPP_ALT: The Locality Preserving Projections (LPP) value (Thompson et al. 2015a), as computed using the alternate detrending, is above threshold. This indicates that the TCE is not transit-shaped, and thus is dispositioned as an FP with the not transit-like major flag set.
  • LPP_DV: The Locality Preserving Projections (LPP) value (Thompson et al. 2015a), as computed using the DV detrending, is above threshold. This indicates that the TCE is not transit-shaped, and thus is dispositioned as an FP with the not transit-like major flag set.
  • MOD_NONUNIQ_ALT: The Modelshift 1 test, performed with the alternate detrending, is below threshold. This test calculates the significance of the primary event, taking into account red noise, and compares it to the false alarm threshold. This flag indicates the primary event is not significant compared to the amount of systematic noise in the light curve, and thus the TCE is dispositioned as an FP with the not transit-like major flag set.
  • MOD_NONUNIQ_DV: The Modelshift 1 test, performed with the DV detrending, is below threshold. This test calculates the significance of the primary event, taking into account red noise, and compares it to the false alarm threshold. This flag indicates the primary event is not significant compared to the amount of systematic noise in the light curve, and thus the TCE is dispositioned as an FP with the not transit-like major flag set.
  • MOD_ODDEVEN_ALT: The odd/even statistic from the Modelshift test is calculated with the alternate detrending. This statistic compares the best-fit transit model to the odd and even transits separately and determines that the difference in the resulting significances is above threshold. When set, the transit-like TCE is dispositioned as an FP with the stellar eclipse major flag set.
  • MOD_ODDEVEN_DV: The odd/even statistic from the Modelshift test is calculated with the DV detrending. This statistic compares the best-fit transit model to the odd and even transits separately and determines that the difference in the resulting significances is above threshold. When set, the transit-like TCE is dispositioned as an FP with the stellar eclipse major flag set.
  • MOD_POS_ALT: The Modelshift 3 test, performed with the alternate detrending, is below threshold. This test compares the significance of the primary and positive-going events in the phased light curve to help determine whether the primary event is unique. This flag indicates that the TCE is likely noise and thus is dispositioned as an FP with the not transit-like major flag set.
  • MOD_POS_DV: The Modelshift 3 test, performed with the DV detrending, is below threshold. This test compares the significance of the primary and positive-going events in the phased light curve to help determine whether the primary event is unique. This flag indicates that the TCE is likely noise and thus is dispositioned as an FP with the not transit-like major flag set.
  • MOD_SEC_ALT: The Modelshift 4, 5, and 6 values, calculated using the alternate detrending, are above threshold. This test calculates the significance of the secondary event divided by Fred, the ratio of red noise to white noise in the light curve. The same calculation is done for the difference between the secondary and tertiary event significances, and the difference between the secondary and positive event significances. They indicate that there is a unique and significant secondary event in the light curve (i.e., a secondary eclipse). Thus, assuming the PLANET_OCCULT_ALT flag is not set, the TCE is dispositioned as an FP with the stellar eclipse major flag set.
  • MOD_SEC_DV: The Modelshift 4, 5, and 6 values, calculated using the DV detrending, are above threshold. This test calculates the significance of the secondary event divided by Fred, the ratio of red noise to white noise in the light curve. The same calculation is done for the difference between the secondary and tertiary event significances, and the difference between the secondary and positive event significances. They indicate that there is a unique and significant secondary event in the light curve (i.e., a secondary eclipse). Thus, assuming the PLANET_OCCULT_DV flag is not set, the TCE is dispositioned as an FP with the stellar eclipse major flag set.
  • MOD_TER_ALT: The Modelshift 2 test, performed with the alternate detrending, is below threshold. This test calculates the difference between the primary and tertiary event significances. This flag indicates that the primary event is not unique in the phased light curve, and thus the TCE is likely noise and dispositioned as an FP with the not transit-like major flag set.
  • MOD_TER_DV: The Modelshift 2 test, performed with the DV detrending, is below threshold. This test calculates the difference between the primary and tertiary event significances. This flag indicates that the primary event is not unique in the phased light curve, and thus the TCE is likely noise and dispositioned as an FP with the not transit-like major flag set.
  • NO_FITS: Both the trapezoidal and the original DV transit fits failed to converge. This indicates the signal is not sufficiently transit-shaped in either detrending to be fit by a transit model. The TCE is dispositioned as an FP with the not transit-like major flag set.
  • PERIOD_ALIAS_ALT: Using the phases of the primary, secondary, and tertiary events from the Modelshift test run on the alternate detrended data, a possible period alias is seen at a ratio of n:1, where n is an integer of 3 or greater. This indicates the TCE has likely been detected at a period that is n times longer than the true orbital period. This flag is currently informational only and not used to declare any TCE an FP.
  • PERIOD_ALIAS_DV: Using the phases of the primary, secondary, and tertiary events from the Modelshift test run on the DV detrended data, a possible period alias is seen at n:1, where n is an integer of 3 or greater. This indicates the TCE has likely been detected at a period that is n times longer than the true orbital period. This flag is currently informational only and not used to declare any TCE an FP.
  • PLANET_IN_STAR: The original DV planet fits indicate that the fitted semi-major axis of the planet is smaller than the stellar radius. As it is possible that the stellar data is not accurate, this flag is currently informational only and not used to declare any TCE an FP.
  • PLANET_OCCULT_ALT: A significant secondary eclipse was detected in the alternate detrending, but it was determined to possibly be due to planetary reflection and/or thermal emission. While the stellar eclipse major flag remains set, the TCE is dispositioned as a PC.
  • PLANET_OCCULT_DV: A significant secondary eclipse was detected in the DV detrending, but it was determined to possibly be due to planetary reflection and/or thermal emission. While the stellar eclipse major flag remains set, the TCE is dispositioned as a PC.
  • PLANET_PERIOD_IS_HALF_ALT: A significant secondary eclipse was detected in the alternate detrending, but it was determined to be the same depth as the primary within the uncertainties. Thus, the TCE is possibly a PC that was detected at twice the true orbital period. When this flag is set, it acts as an override to other flags such that the stellar eclipse major flag is not set, and thus the TCE is dispositioned as a PC if no other major flags are set.
  • PLANET_PERIOD_IS_HALF_DV: A significant secondary eclipse was detected in the DV detrending, but it was determined to be the same depth as the primary within the uncertainties. Thus, the TCE is possibly a PC that was detected at twice the true orbital period. When this flag is set, it acts as an override to other flags such that the stellar eclipse major flag is not set, and thus the TCE is dispositioned as a PC if no other major flags are set.
  • RESIDUAL_TCE: The TCE has the same period and epoch as a previous transit-like TCE. This indicates the current TCE is simply a residual artifact of the previous TCE that was not completely removed from the light curve. Thus, the current TCE is dispositioned as an FP with the not transit-like major flag set.
  • SAME_NTL_PERIOD: The current TCE has the same period as a previous TCE that was dispositioned as an FP with the not transit-like major flag set. This indicates that the current TCE is due to the same not transit-like signal. Thus, the current TCE is dispositioned as an FP with the not transit-like major flag set.
  • SEASONAL_DEPTH_ALT: There appears to be a significant difference in the computed TCE depth from different seasons using the ALT detrending. This indicates significant light contamination, usually due to a bright star at the edge of the aperture, which may or may not be the origin of the transit-like event. As it is impossible to determine whether or not the TCE is on-target from this flag alone, it is currently informational only and not used to declare any TCE an FP.
  • SEASONAL_DEPTH_DV: There appears to be a significant difference in the computed TCE depth from different seasons using the DV detrending. This indicates significant light contamination, usually due to a bright star at the edge of the aperture, which may or may not be the origin of the transit-like event. As it is impossible to determine whether or not the TCE is on-target from this flag alone, it is currently informational only and not used to declare any TCE an FP.
  • SWEET_EB: The sine wave event evaluation test (SWEET) is above threshold, the detected signal has an amplitude less than the TCE's depth, and the TCE period is less than 5 days. This flag indicates that there is a significant sinusoidal variability in the PDC data at the same period as the TCE, and the detected event is due to out-of-eclipse EB variability. The transit-like TCE is dispositioned as an FP with the stellar eclipse major flag set.
  • SWEET_NTL: The sine wave event evaluation test (SWEET) is above threshold, the detected signal has an amplitude greater than the TCE's depth, and the TCE period is less than 5 days. This flag indicates that there is a significant sinusoidal variability in the PDC data at the same period as the TCE, and the detected event is due to stellar variability and not a transit. The TCE is dispositioned as an FP with the not transit-like major flag set.
  • TRANS_GAPPED: The fraction of gapped transit events is above threshold. This flag indicates that a large number of observable transits had insufficient in-cadence data. The TCE is dispositioned as an FP with the not transit-like major flag set.

DR 24 KOI Robovetter Minor Flags

In the DR24 KOI table (Coughlin et al. 2016) the comment field also displays the minor flags from the Robovetter, similar to the DR25 table above. In alphabetical order, the DR24 Robovetter minor flags are:

  • ALT_ROBO_ODD_EVEN_TEST_FAIL: The TCE failed the Robovetter's odd-even depth test on the alternate detrending, and thus is marked as an FP due to a significant secondary.
  • ALT_SEC_COULD_BE_DUE_TO_PLANET: A significant secondary eclipse was detected in the alternate detrending, but it was determined to possibly be due to planetary reflection. While the significant secondary major flag remains set, the TCE is dispositioned as a PC.
  • ALT_SEC_SAME_DEPTH_AS_PRI_COULD_BE_TWICE_TRUE_PERIOD: A significant secondary eclipse was detected in the alternate detrending, but it was determined to be the same depth as the primary within the uncertainties. Thus, the TCE is possibly a PC that was detected at twice the true orbital period. When this flag is set, it acts as an override to other flags such that the significant secondary major flag is not set, and thus the TCE is dispositioned as a PC if no other major flags are set.
  • ALT_SIG_PRI_MINUS_SIG_POS_TOO_LOW: The difference of the primary and positive event significances, computed by the model-shift test using the alternate detrending, is below the threshold σ′FA. This indicates the primary event is not unique in the phased light curve, and thus the TCE is dispositioned as a FP with the not transit-like major flag set.
  • ALT_SIG_PRI_MINUS_SIG_TER_TOO_LOW: The difference of the primary and tertiary event significances, computed by the model-shift test using the alternate detrending, is below the threshold σ′FA. This indicates the primary event is not unique in the phased light curve, and thus the TCE is dispositioned as a FP with the not transit-like major flag set.
  • ALT_SIG_PRI_OVER_FRED_TOO_LOW: The significance of the primary event divided by the ratio of red noise to white noise in the light curve, computed by the model-shift test using the alternate detrending, is below the threshold σFA. This indicates the primary event is not significant compared to the amount of systematic noise in the light curve, and thus the TCE is dispositioned as a FP with the not transit-like major flag set.
  • CENTROID_SIGNIF_UNCERTAIN: The uncertainty in the offset significance is high enough that the centroid module can not confidently say whether the significance is above or below the threshold. This flag typically gets set for TCEs with only 3 or 4 recorded centroid measurements.
  • CLEAR_APO: The TCE was marked as a FP due to a centroid offset because the transit occurs on a star that is spatially resolved from the target.
  • CROWDED_DIFF: More than one potential stellar image was found in the difference image. The EYEBALL flag is always set when the CROWDED_DIFF flag is set.
  • DV_ROBO_ODD_EVEN_TEST_FAIL: The TCE failed the Robovetter's odd-even depth test on the DV detrending, and thus is marked as a FP due to a significant secondary.
  • DV_SEC_COULD_BE_DUE_TO_PLANET: A significant secondary eclipse was detected in the DV detrending, but it was determined to possibly be due to planetary reflection. While the significant secondary major flag remains set, the TCE is dispositioned as a PC.
  • DV_SEC_SAME_DEPTH_AS_PRI_COULD_BE_TWICE_TRUE_PERIOD: A significant secondary eclipse was detected in the DV detrending, but it was determined to be the same depth as the primary within the uncertainties. Thus, the TCE is possibly a PC that was detected at twice the true orbital period. When this flag is set, it acts as an override to other flags such that the significant secondary major flag is not set, and thus the TCE is dispositioned as a PC if no other major flags are set.
  • DV_SIG_PRI_MINUS_SIG_POS_TOO_LOW: The difference of the primary and positive event significances, computed by the model-shift test using the DV detrending, is below the threshold σ′FA. This indicates the primary event is not unique in the phased light curve, and thus the TCE is dispositioned as a FP with the not transit-like major flag set.
  • DV_SIG_PRI_MINUS_SIG_TER_TOO_LOW: The difference of the primary and tertiary event significances, computed by the model-shift test using the DV detrending, is below the threshold σ′FA. This indicates the primary event is not unique in the phased light curve, and thus the TCE is dispositioned as a FP with the not transit-like major flag set.
  • DV_SIG_PRI_OVER_FRED_TOO_LOW: The significance of the primary event divided by the ratio of red noise to white noise in the light curve, computed by the model-shift test using the DV detrending, is below the threshold σFA. This indicates the primary event is not significant compared to the amount of systematic noise in the light curve, and thus the TCE is dispositioned as a FP with the not transit-like major flag set.
  • EYEBALL: The metrics used by the centroid module are very close to the decision boundaries, and thus the centroid disposition of this TCE is uncertain and warrants further scrutiny. No TCEs are marked as a FP due to a centroid offset if this flag is set.
  • FIT_FAILED: The transit was not fit by a model in DV and thus no difference images were created for use by the centroid module. Thus, the TCE is not failed due to a centroid offset by default. This flag is typically set for very deep transits due to eclipsing binaries.
  • INVERT_DIFF: One or more difference images were inverted, meaning the difference image claims the star got brighter during transit. This is usually due to variability of the target star and suggests the difference image should not be trusted. When this flag is set, the TCE is marked as a candidate that requires further scrutiny, i.e., the EYEBALL flag is set and the TCE is not marked as a FP due to a centroid offset.
  • KIC_OFFSET: The centroid module measured the offset distance relative to the star's recorded position in the Kepler Input Catalog (KIC), not the out of transit centroid. The KIC position is less accurate in sparse fields, but more accurate in crowded fields. If this is the only flag set, there is no reason to believe a statistically significant centroid shift is present (Mullally et al. 2015).
  • LPP_ALT_TOO_HIGH: The LPP value (Thompson et al. 2015), as computed using the alternate detrending, is above the Robovetter threshold. This indicates the TCE is not transit-shaped, and thus is dispositioned as a FP with the not transit-like major flag set.
  • LPP_DV_TOO_HIGH: The LPP value, as computed using the DV detrending, is above the Robovetter threshold. This indicates the TCE is not transit-shaped, and thus is dispositioned as a FP with the not transit-like major flag set.
  • MARSHALL_FAIL: The TCE failed the "Marshall" test (Mullally et al. 2015, submitted), which indicates that the TCE's individual transits are not transit-shaped and more likely due to instrumental artifacts. Thus, the TCE is dispositioned as a FP with the not transit-like major flag set.
  • OTHER_TCE_AT_SAME_PERIOD_DIFF_EPOCH: Another TCE on the same target with a higher planet number was found to have the same period as the current TCE, but a significantly different epoch. This indicates the current TCE is an eclipsing binary with the other TCE representing the secondary eclipse. If the ALT_SEC_COULD_BE_DUE_TO_PLANET and DV_SEC_COULD_BE_DUE_TO_PLANET flags are not set, the TCE is dispositioned as a FP with the significant secondary major flag set.
  • PARENT_IS_X: The TCE has been identified as a FP due to an ephemeris match. This minor flag indicates the most likely parent, or true physical source of the signal, where X will be substituted for the parent's name. Note that X is not guaranteed to be the true parent, but simply is the most likely source given the information available.
  • PERIOD_ALIAS_IN_ALT_DATA_SEEN_AT_X:1: Using the results of the model-shift test (specifically the phases of the primary, secondary, and tertiary events) a possible period alias is seen at X:1, where X is an integer. This indicates the TCE has likely been detected at a period that is X times longer than the true orbital period. This flag is currently informational only and not used to declare any TCE a FP.
  • RESID_OF_PREV_TCE: The TCE has the same period and epoch as a previous transit-like TCE. This indicates the current TCE is simply a residual artifact of the previous TCE after it was removed from the light curve. Thus, the current TCE is dispositioned as a FP with the not transit-like major flag set.
  • SAME_P_AS_PREV_NTL_TCE: The current TCE has the same period as a previous TCE that was dispositioned as FP with the not transit-like major flag set. This indicates that the current TCE is due to the same not transit-like signal. Thus, the current TCE is dispositioned as a FP with the not transit-like major flag set.
  • SATURATED: The star is saturated. The assumptions employed by the centroid Robovetter module break down for saturated stars, so the TCE is marked as a candidate requiring further scrutiny, i.e., the EYEBALL flag is set and the TCE is not marked as a FP due to a centroid offset.
  • SEASONAL_DEPTH_DIFFS_IN_ALT: There appears to be a significant difference in the computed TCE depth when using the alternate detrending light curves from different seasons. This indicates significant light contamination is present, usually due to a bright star at the edge of the image, which may or may not be the source of the signal. As it is impossible to determine whether or not the TCE is on-target from this flag alone, it is currently informational only and not used to declare any TCE a FP.
  • SEASONAL_DEPTH_DIFFS_IN_DV: There appears to be a significant difference in the computed TCE depth when using the DV detrending light curves from different seasons. This indicates significant light contamination is present, usually due to a bright star at the edge of the image, which may or may not be the source of the signal. As it is impossible to determine whether or not the TCE is on-target from this flag alone, it is currently informational only and not used to declare any TCE a FP.
  • SIG_SEC_IN_ALT_MODEL_SHIFT: The significance of the secondary event divided by the ratio of red noise to white noise in the light curve, computed by the model-shift test using the alternate detrending, is above the threshold σFA. As well, the difference between the secondary and tertiary event significances, and the difference between the secondary and positive event significances, both computed by the model-shift test using the alternate detrending, is above the threshold σ′FA. This indicates that there is a unique and significant secondary event in the light curve, i.e., a secondary eclipse. Thus, assuming the ALT_SEC_COULD_BE_DUE_TO_PLANET flag is not set, the TCE is dispositioned as a FP with the significant secondary flag set.
  • SIG_SEC_IN_DV_MODEL_SHIFT: The significance of the secondary event divided by the ratio of red noise to white noise in the light curve, computed by the model-shift test using the DV detrending, is above the threshold σFA. As well, the difference between the secondary and tertiary event significances, and the difference between the secondary and positive event significances, both computed by the model-shift test using the DV detrending, is above the threshold σ′FA. This indicates that there is a unique and significant secondary event in the light curve, i.e., a secondary eclipse. Thus, assuming the DV_SEC_COULD_BE_DUE_TO_PLANET flag is not set, the TCE is dispositioned as a FP with the significant secondary flag set.
  • SIGNIF_OFFSET: There is a statistically significant shift in the centroid during transit. This indicates the variability is not due to the target star. Thus, the TCE is dispositioned as a FP with the centroid offset major flag set.
  • THIS_TCE_IS_A_SEC: The TCE is determined to have the same period, but different epoch, as a previous transit-like TCE. This indicates that the current TCE corresponds to the secondary eclipse of an eclipsing binary (or planet if the ALT_SEC_COULD_BE_DUE_TO_PLANET or DV_SEC_COULD_BE_DUE_TO_PLANET flags are set.) Thus, the current TCE is dispositioned as a FP with both the not transit-like and significant secondary major flags set.
  • TOO_FEW_CENTROIDS: The PRF centroid fit used by the centroid module does not always converge, even in high SNR difference images. This flag is set if centroid offsets are recorded for fewer than 3 high SNR difference images.
  • TOO_FEW_QUARTERS: Fewer than 3 difference images of sufficiently high SNR are available, and thus very few tests in the centroid module are applicable to the TCE. If this flag is set in conjunction with the CLEAR_APO flag, the source of the transit may be on a star clearly resolved from the target.
  • TRANSITS_NOT_CONSISTENT: The TCE had a ratio of the maximum SES value (tce_max_sngle_ev) to the MES value (tce_max_mult_ev) greater than 0.9, and a period greater than 90 days. This indicates that the TCE is dominated by a single large event, and thus is due to a systematic feature such as a sudden pixel sensitivity dropout. Thus, the TCE is dispositioned as a FP with the not transit-like major flag set.


Last updated: 11 July 2017