Kepler Astrophysical False Positive Probabilities Table Description

This table contains the results of running an automated transit false-positive-probability (FPP) calculating procedure on all KOIs. This procedure was first documented in Morton (2012) and has evolved slightly since then, with the most current description being in Montet et al. (2015).  The code used to implement this procedure is the Python module vespa, which is freely available online at https://github.com/timothydmorton/vespa.

A key part of these calculations involves estimating the posterior probability distributions of the physical parameters of the transit host stars, which are modeled as single, binary, and triple systems and constrained by both broad-band photometry and spectroscopy (when available). The vespa code uses the isochrones module to accomplish this, and the summary results of the single-star fits are presented in this table alongside the FPP results. 

These FPP calculations represent an additional level of analysis that might help determine which KOIs are planets and which are false positives. The results of this analysis have not yet been incorporated into any of the other Kepler data products. Consequently, they have not influenced the robovetter dispositions provided in the Q1-Q17 DR24 KOI table (Coughlin et al. 2015) or the autovetter dispositions provided in the Q1-Q17 DR24 TCE table (Catanzarite et al., 2015). Hence, these results could address the reliability of these catalogs by identifying residual false positives. Of course, it is also possible that one of the key assumptions of the FPP calculation is violated (e.g., the "exclusion radius" inside of which a blended eclipsing binary false positive might live could be underestimated) or the transit signature is an instrumental artifact that is not properly modeled by this analysis.



Last updated: 2 December 2015