Searching for exoplanets using artificial intelligence

• Published in: Monthly notices of the Royal Astronomical Society Vol. 474; no. 1; pp. 478 - 491
• Main Authors: Pearson, Kyle A., Palafox, Leon, Griffith, Caitlin A.
• Format: Journal Article
• Language: English
• Published: London Oxford University Press 01.02.2018
• Subjects: Artificial intelligence; Artificial neural networks; Astronomy; Extrasolar planets; Feature recognition; Human error; Interpolation; Least squares method; Machine learning; Neural networks; Planet detection; Time series; Transits; planets and satellites: detection; techniques: photometric; methods: data analysis
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stx2761

Abstract In the last decade, over a million stars were monitored to detect transiting planets. Manual interpretation of potential exoplanet candidates is labour intensive and subject to human error, the results of which are difficult to quantify. Here we present a new method of detecting exoplanet candidates in large planetary search projects that, unlike current methods, uses a neural network. Neural networks, also called ‘deep learning’ or ‘deep nets’, are designed to give a computer perception into a specific problem by training it to recognize patterns. Unlike past transit detection algorithms, deep nets learn to recognize planet features instead of relying on hand-coded metrics that humans perceive as the most representative. Our convolutional neural network is capable of detecting Earth-like exoplanets in noisy time series data with a greater accuracy than a least-squares method. Deep nets are highly generalizable allowing data to be evaluated from different time series after interpolation without compromising performance. As validated by our deep net analysis of Kepler light curves, we detect periodic transits consistent with the true period without any model fitting. Our study indicates that machine learning will facilitate the characterization of exoplanets in future analysis of large astronomy data sets.