Single Transit Detection In Kepler With Machine Learning And Onboard Spacecraft Diagnostics
This addresses the dearth of exoplanet discoveries at long periods for astronomers, offering a new pipeline to potentially find more planets in the Kepler dataset, including in the η-Earth regime, though it is incremental as it builds on existing machine learning methods.
The paper tackles the problem of detecting exoplanets at long orbital periods by developing a novel technique using an ensemble of Convolutional Neural Networks with Kepler spacecraft diagnostics to classify transits, achieving >80% sensitivity out to 800-day periods and reporting a candidate planet with a radius of 5.32 ± 0.20 R⊕ and mass of 28.94 M⊕.
Exoplanet discovery at long orbital periods requires reliably detecting individual transits without additional information about the system. Techniques like phase-folding of light curves and periodogram analysis of radial velocity data are more sensitive to planets with shorter orbital periods, leaving a dearth of planet discoveries at long periods. We present a novel technique using an ensemble of Convolutional Neural Networks incorporating the onboard spacecraft diagnostics of \emph{Kepler} to classify transits within a light curve. We create a pipeline to recover the location of individual transits, and the period of the orbiting planet, which maintains $>80\%$ transit recovery sensitivity out to an 800-day orbital period. Our neural network pipeline has the potential to discover additional planets in the \emph{Kepler} dataset, and crucially, within the $η$-Earth regime. We report our first candidate from this pipeline, KOI 1271.02. KOI 1271.01 is known to exhibit strong Transit Timing Variations (TTVs), and so we jointly model the TTVs and transits of both transiting planets to constrain the orbital configuration and planetary parameters and conclude with a series of potential parameters for KOI 1271.02, as there is not enough data currently to uniquely constrain the system. We conclude that KOI 1271.02 has a radius of 5.32 $\pm$ 0.20 $R_{\oplus}$ and a mass of $28.94^{0.23}_{-0.47}$ $M_{\oplus}$. Future constraints on the nature of KOI 1271.02 require measuring additional TTVs of KOI 1271.01 or observing a second transit of KOI 1271.02.