Identifying Exoplanets with Deep Learning. III. Automated Triage and Vetting of TESS Candidates

NASA's Transiting Exoplanet Survey Satellite (TESS) presents us with an unprecedented volume of space-based photometric observations that must be analyzed in an efficient and unbiased manner. With at least $\sim1,000,000$ new light curves generated every month from full frame images alone, automated planet candidate identification has become an attractive alternative to human vetting. Here we present a deep learning model capable of performing triage and vetting on TESS candidates. Our model is modified from an existing neural network designed to automatically classify Kepler candidates, and is the first neural network to be trained and tested on real TESS data. In triage mode, our model can distinguish transit-like signals (planet candidates and eclipsing binaries) from stellar variability and instrumental noise with an average precision (the weighted mean of precisions over all classification thresholds) of 97.0% and an accuracy of 97.4%. In vetting mode, the model is trained to identify only planet candidates with the help of newly added scientific domain knowledge, and achieves an average precision of 69.3% and an accuracy of 97.8%. We apply our model on new data from Sector 6, and present 288 new signals that received the highest scores in triage and vetting and were also identified as planet candidates by human vetters. We also provide a homogeneously classified set of TESS candidates suitable for future training.

[1]  Martín Abadi,et al.  TensorFlow: Large-Scale Machine Learning on Heterogeneous Distributed Systems , 2016, ArXiv.

[2]  Chelsea X. Huang,et al.  A TESS Dress Rehearsal: Planetary Candidates and Variables from K2 Campaign 17 , 2018, The Astrophysical Journal Supplement Series.

[3]  M. Auvergne,et al.  The CoRoT satellite in flight : description and performance , 2009, 0901.2206.

[4]  E. Bachelet,et al.  SIDRA: a blind algorithm for signal detection in photometric surveys , 2015, 1511.03456.

[5]  Mark Clampin,et al.  Transiting Exoplanet Survey Satellite , 2014, 1406.0151.

[6]  Daniel Angerhausen,et al.  Rapid classification of TESS planet candidates with convolutional neural networks , 2019, Astronomy & Astrophysics.

[7]  Chelsea X. Huang,et al.  TESS Full Orbital Phase Curve of the WASP-18b System , 2018, The Astronomical Journal.

[8]  Drake Deming,et al.  THE TRANSITING EXOPLANET SURVEY SATELLITE: SIMULATIONS OF PLANET DETECTIONS AND ASTROPHYSICAL FALSE POSITIVES , 2015, 1506.03845.

[9]  Jason T. Wright,et al.  A disintegrating minor planet transiting a white dwarf , 2015, Nature.

[10]  R. G. West,et al.  An orbital period of 0.94 days for the hot-Jupiter planet WASP-18b , 2009, Nature.

[11]  David J Armstrong,et al.  Machine-learning approaches to exoplanet transit detection and candidate validation in wide-field ground-based surveys , 2018, Monthly Notices of the Royal Astronomical Society.

[12]  A. D. Feinstein,et al.  Planetary Candidates from K2 Campaign 16 , 2018, The Astronomical Journal.

[13]  F. Mullally,et al.  The K2 Mission: Characterization and Early Results , 2014, 1402.5163.

[14]  Sara Seager,et al.  TESS Discovery of an Ultra-short-period Planet around the Nearby M Dwarf LHS 3844 , 2018, The Astrophysical Journal.

[15]  David Charbonneau,et al.  TrES-1: The Transiting Planet of a Bright K0 V Star , 2004 .

[16]  A. Vanderburg,et al.  A Technique for Extracting Highly Precise Photometry for the Two-Wheeled Kepler Mission , 2014, 1408.3853.

[17]  M. R. Haas,et al.  Kepler Mission Design, Realized Photometric Performance, and Early Science , 2010, 1001.0268.

[18]  B. Enoch,et al.  The WASP Project and the SuperWASP Cameras , 2006, astro-ph/0608454.

[19]  Michael C. Liu,et al.  197 CANDIDATES AND 104 VALIDATED PLANETS IN K2's FIRST FIVE FIELDS , 2016, 1607.05263.

[20]  Clea F. Schumer,et al.  275 Candidates and 149 Validated Planets Orbiting Bright Stars in K2 Campaigns 0–10 , 2018, 1802.05277.

[21]  K. Stanek,et al.  Wide‐Field Millimagnitude Photometry with the HAT: A Tool for Extrasolar Planet Detection , 2004, astro-ph/0401219.

[22]  W. Borucki,et al.  KEPLER Mission: development and overview , 2016, Reports on progress in physics. Physical Society.

[23]  George R. Ricker,et al.  Expected Yields of Planet discoveries from the TESS primary and extended missions , 2018, 1807.11129.

[24]  Bruce D. Clarke,et al.  Identifying False Alarms in the Kepler Planet Candidate Catalog , 2016, 1602.03204.

[25]  David J Armstrong,et al.  Transit shapes and self-organizing maps as a tool for ranking planetary candidates: application to Kepler and K2 , 2016, 1611.01968.

[26]  P. Tenenbaum,et al.  AUTOMATIC CLASSIFICATION OF KEPLER PLANETARY TRANSIT CANDIDATES , 2014, 1408.1496.

[27]  P. Berlind,et al.  PLANETARY CANDIDATES FROM THE FIRST YEAR OF THE K2 MISSION , 2015, 1511.07820.

[28]  Keivan G. Stassun,et al.  An Eccentric Massive Jupiter Orbiting a Subgiant on a 9.5-day Period Discovered in the Transiting Exoplanet Survey Satellite Full Frame Images , 2019, The Astronomical Journal.

[29]  Liang Yu,et al.  Identifying Exoplanets with Deep Learning. II. Two New Super-Earths Uncovered by a Neural Network in K2 Data , 2019, The Astronomical Journal.

[30]  Leslie Hebb,et al.  The EBLM Project IV. Spectroscopic orbits of over 100 eclipsing M dwarfs masquerading as transiting hot-Jupiters , 2017, 1707.07521.

[31]  Chelsea X. Huang,et al.  TESS Discovery of a Transiting Super-Earth in the pi Mensae System , 2018, The astrophysical journal. Letters.

[32]  Khadeejah A. Zamudio,et al.  PLANETARY CANDIDATES OBSERVED BY KEPLER. VII. THE FIRST FULLY UNIFORM CATALOG BASED ON THE ENTIRE 48-MONTH DATA SET (Q1–Q17 DR24) , 2015, 1512.06149.

[33]  G. Kov'acs,et al.  A box-fitting algorithm in the search for periodic transits , 2002, astro-ph/0206099.

[34]  Norman S. Kopeika,et al.  Optical, infrared, and millimeter wave propagation engineering , 1988 .

[35]  Kyle A. Pearson,et al.  Searching for exoplanets using artificial intelligence , 2017, Monthly Notices of the Royal Astronomical Society.

[36]  Raja Giryes,et al.  Shallow Transits—Deep Learning. I. Feasibility Study of Deep Learning to Detect Periodic Transits of Exoplanets , 2017, 1711.03163.

[37]  Joel D. Hartman,et al.  Vartools: A program for analyzing astronomical time-series data , 2016, Astron. Comput..

[38]  Christopher J. Shallue,et al.  Identifying Exoplanets with Deep Learning: A Five-planet Resonant Chain around Kepler-80 and an Eighth Planet around Kepler-90 , 2017, 1712.05044.

[39]  Jimmy Ba,et al.  Adam: A Method for Stochastic Optimization , 2014, ICLR.

[40]  M. R. Haas,et al.  A MACHINE LEARNING TECHNIQUE TO IDENTIFY TRANSIT SHAPED SIGNALS , 2015, 1509.00041.

[41]  M. Sasdelli,et al.  Scientific Domain Knowledge Improves Exoplanet Transit Classification with Deep Learning , 2018, The Astrophysical Journal.

[42]  S. Lynn,et al.  Planet Hunters IX. KIC 8462852-where's the flux? , 2015, 1509.03622.

[43]  Mark Clampin,et al.  Transiting Exoplanet Survey Satellite (TESS) , 2014, Astronomical Telescopes and Instrumentation.

[44]  Howard Isaacson,et al.  Kepler Planet-Detection Mission: Introduction and First Results , 2010, Science.

[45]  G. Bruce Berriman,et al.  The KELT Follow-up Network and Transit False-positive Catalog: Pre-vetted False Positives for TESS , 2018, The Astronomical Journal.