Planetary Candidates Observed by Kepler. VIII. A Fully Automated Catalog with Measured Completeness and Reliability Based on Data Release 25

Abstract

We present the Kepler Object of Interest (KOI) catalog of transiting exoplanets based on searching 4 yr of Kepler time series photometry (Data Release 25, Q1-Q17). The catalog contains 8054 KOIs, of which 4034 are planet candidates with periods between 0.25and 632days. Of these candidates, 219 are new, including two in multiplanet systems (KOI-82.06 and KOI-2926.05) and 10 high-reliability, terrestrial-size, habitable zone candidates. This catalog was created using a tool called the Robovetter, which automatically vets the DR25 threshold crossing events (TCEs). The Robovetter also vetted simulated data sets and measured how well it was able to separate TCEs caused by noise from those caused by low signal-to-noise transits. We discuss the Robovetter and the metrics it uses to sort TCEs. For orbital periods less than 100 days the Robovetter completeness (the fraction of simulated transits that are determined to be planet candidates) across all observed stars is greater 1 than 85%. For the same period range, the catalog reliability (the fraction of candidates that are not due to instrumental or stellar noise) is greater than 98%. However, for low signal-to-noise candidates between 200 and 500 days around FGK-dwarf stars, the Robovetter is 76.7% complete and the catalog is 50.5% reliable. The KOI catalog, the transit fits, and all of the simulated data used to characterize this catalog are available at the NASA Exoplanet Archive.

Robo-AO Kepler Survey. V. The Effect of Physically Associated Stellar Companions on Planetary Systems

“…The planet catalog does not correct for dilution from stars detected from high-resolution imaging as these observations are typically only available for KOIs and could bias occurrence rate estimates (Thompson et al 2018). …”

Searching the Entirety of Kepler Data. I. 17 New Planet Candidates Including One Habitable Zone World

“…The main difference between our search and Kepler 's is our use of a Box-Least Squares (BLS) algorithm (Kovács et al 2002) and the associated effective BLS signalto-noise ratio (S/N) for measuring the significance of a detection, instead of a wavelet-based algorithm (Jenkins et al 2010) and the associated Multiple Event Statistic (MES). Furthermore, while our vetting is largely inspired by the automated DR25 Robovetter (Thompson et al 2018), we introduce different tests and follow our automated vetting with a final manual vetting stage, similar to Petigura et al (2013).…”

“…Ultraprecise photometry from space satellites like NASA's Kepler mission has lead to a revolution in the discovery and characterization of planets beyond the solar system. Launched in 2009, Kepler alone has confirmed 2345 planets out of 4765 announced candidates 1 from its original four year mission, accounting for more than half of all planets known today (Borucki et al 2010(Borucki et al , 2011Batalha et al 2013;Burke et al 2014;Mullally et al 2015;Rowe et al 2015;Coughlin et al 2016; Thompson et al 2018).…”

“…Even following the release of Kepler catalogues based on all four years of Kepler data (Coughlin et al 2016; Thompson et al 2018), independent authors have shown that there are still scientifically interesting candidates to be found. Shallue & Vanderburg (2018) represents the first application of machine learning to searching Kepler data for exoplanets, finding two new planets among a subset of Q1−Q17 KOIs including an eighth planet in a planetary system.…”

A Gap in the Mass Distribution for Warm Neptune and Terrestrial Planets

“…For planets with known radii, which in our sample were all measured by the transit method, there is a bias against low (R p /R * ) 2 due to decreasing signal strength, and large semi-major axis a as the probability of transit decreases with 1/a and is limited by mission baseline. Most transiting planets in the sample were discovered via the Kepler mission, for which the detection efficiency falls for planets with periods longer than several hundred days, and radii smaller than ∼1-2R ⊕ for FGK dwarf stars (Thompson et al 2018), well outside the range covered by the gap. For ground based photometric surveys and to a lesser extent K2 the period and radius sensitivity is more relevant, with ground based surveys in particular struggling to detect planets of Earth and Neptune size aside from a handful of cases with M dwarf host stars.…”