An Independent Planet Search In The Kepler Dataset. I. A hundred new candidates and revised KOIs

TL;DR

This study re-analyzed Kepler data using an alternative pipeline, discovering 84 new transit signals, updating planetary system statistics, and validating several new planet candidates, thereby enhancing our understanding of exoplanet multiplicity.

Contribution

The paper introduces a new analysis pipeline applied to Kepler data, significantly increasing the number of known transit signals and refining planetary system statistics.

Findings

Discovered 84 new transit signals in Kepler data.

Identified new multi-planet systems, including KOI 435.

Validated several small planet candidates in habitable zones.

Abstract

Aims. We present our re-analyze the Kepler photometric dataset, searching for planetary transits using an alternative processing pipeline to the one used by the Kepler Mission. Methods. The SARS pipeline was tested extensively by processing all available CoRoT data. We used this pipeline to search for (additional) planetary transits only in the Kepler objects of interest (KOIs). Results. Although less than 1% of the Kepler dataset are KOIs we are able to significantly update the overall statistics of planetary multiplicity: we find 84 new transit signals on 64 systems on these light curves only, nearly doubling the number of transit signals in these systems. Forty-one of the systems were singly-transiting systems that are now multiply-transiting. Notable among the new discoveries are KOI 435 as a new six-candidate system (of which kind only Kepler-11 was known before), KOI 277 (which includes two candidates in a 6:7 resonance and anti-correlated transit timing variations) - all but validating the system, KOIs 719, 1574, and 1871 that have small planet candidates (1.15, 2.05 and 1.71R_Earth) in the habitable zone of their host star, and KOI 1843 that exhibits the shortest period (4.25hr) and among the smallest (0.63 R_Earth) of all planet candidates. We are also able to reject 11 KOIs as eclipsing binaries, update the ephemeris for five KOIs and otherwise discuss yet other objects. Interestingly, about 1/3 of the newly detected candidates participate in period commensurabilities. Finally, we discuss the possible overestimation of parameter errors in the current list of KOIs. Conclusions. Our results strengthen previous analyses of the multi-transiting ensemble. Nevertheless, we conclude that despite the phenomenal success of the Kepler mission, parallel analysis of the data by multiple teams is required to make full use of the data. [ABRIDGED]