Transit Detection in the MEarth Survey of Nearby M Dwarfs: Bridging the Clean-First, Search-Later Divide

Abstract

In the effort to characterize the masses, radii, and atmospheres of potentially habitable exoplanets, there is an urgent need to find examples of such planets transiting nearby M dwarfs. The MEarth Project is an ongoing effort to do so, as a ground-based photometric survey designed to detect exoplanets as small as 2 Earth radii transiting mid-to-late M dwarfs within 33 pc of the Sun. Unfortunately, identifying transits of such planets in photometric monitoring is complicated both by the intrinsic stellar variability that is common among these stars and by the nocturnal cadence, atmospheric variations, and instrumental systematics that often plague Earth-bound observatories. Here we summarize the properties of MEarth data gathered so far, and we present a new framework to detect shallow exoplanet transits in wiggly and irregularly-spaced light curves. In contrast to previous methods that clean trends from light curves before searching for transits, this framework assesses the significance of individual transits simultaneously while modeling variability, systematics, and the photometric quality of individual nights. Our Method for Including Starspots and Systematics in the Marginalized Probability of a Lone Eclipse (MISS MarPLE) uses a computationally efficient semi-Bayesian approach to explore the vast probability space spanned by the many parameters of this model, naturally incorporating the uncertainties in these parameters into its evaluation of candidate events. We show how to combine individual transits processed by MISS MarPLE into periodic transiting planet candidates and compare our results to the popular Box-fitting Least Squares (BLS) method with simulations. By applying MISS MarPLE to observations from the MEarth Project, we demonstrate the utility of this framework for robustly assessing the false alarm probability of transit signals in real data. [slightly abridged]

accepted to the Astronomical Journal, 21 pages, 12 figures

References in corpus (17)

• The effect of red noise on planetary transit detection
• TrES-1: The Transiting Planet of a Bright K0V Star
• KELT-1b: A Strongly Irradiated, Highly Inflated, Short Period, 27 Jupiter-mass Companion Transiting a mid-F Star
• HATSouth: a global network of fully automated identical wide-field telescopes
• Data analysis recipes: Fitting a model to data
• A White Light Megaflare on the dM4.5e Star YZ CMi
• The Monitor project: Data processing and lightcurve production
• The Monitor project: Searching for occultations in young open clusters
• KELT-2Ab: A Hot Jupiter Transiting the Bright (V=8.77) Primary Star of a Binary System
• Near Infrared Monitoring of Ultracool Dwarfs: Prospects for Searching for Transiting Companions
• Four ultra-short period eclipsing M-dwarf binaries in the WFCAM Transit Survey
• Looking for Super-Earths in the HD 189733 System: A Search for Transits in Most Space-Based Photometry
• De-Trending Time Series for Astronomical Variability Surveys
• Detection of transiting Jovian exoplanets by Gaia photometry - expected yield
• Photometric transit search for planets around cool stars from the western Italian Alps: A pilot study
• Observational Window Functions in Planet Transit Surveys
• Modelling solar-like variability for the detection of Earth-like planetary transits. I. Performance of the three-spot modelling and harmonic function fitting

Cited by in corpus (115)

• The Occurrence Rate of Small Planets around Small Stars
• Helium in the eroding atmosphere of an exoplanet
• The H$\alpha$ emission of nearby M dwarfs and its relation to stellar rotation
• A temperate rocky super-Earth transiting a nearby cool star
• Stellar Flares from the First Tess Data Release: Exploring a New Sample of M-dwarfs
• A Framework for Characterizing the Atmospheres of Low-Mass Low-Density Transiting Planets
• Trumpeting M Dwarfs with CONCH-SHELL: a Catalog of Nearby Cool Host-Stars for Habitable ExopLanets and Life
• The rotation and Galactic kinematics of mid M dwarfs in the Solar Neighborhood
• Transit Least Squares: Optimized transit detection algorithm to search for periodic transits of small planets
• A rocky planet transiting a nearby low-mass star
• Near-infrared Metallicities, Radial Velocities and Spectral Types for 447 Nearby M Dwarfs
• An Activity-Rotation Relationship and Kinematic Analysis of Nearby Mid-to-Late-type M Dwarfs
• The CARMENES search for exoplanets around M dwarfs. Two temperate Earth-mass planet candidates around Teegarden's Star
• A candidate super-Earth planet orbiting near the snow line of Barnard's star
• A global analysis of Spitzer and new HARPS data confirms the loneliness and metal-richness of GJ 436 b
• A giant exoplanet orbiting a very low-mass star challenges planet formation models
• Kepler-445, Kepler-446 and the Occurrence of Compact Multiples Orbiting Mid-M Dwarf Stars
• New rotation period measurements for M dwarfs in the southern hemisphere: an abundance of slowly rotating, fully convective stars
• A second terrestrial planet orbiting the nearby M dwarf LHS 1140
• KELT-20b: A giant planet with a period of P~ 3.5 days transiting the V~ 7.6 early A star HD 185603
• An empirical calibration to estimate cool dwarf fundamental parameters from H-band spectra
• Formation and composition of planets around very low mass stars
• Trigonometric Parallaxes for 1,507 Nearby Mid-to-Late M-dwarfs
• Zodiacal Exoplanets in Time (ZEIT) V: A Uniform Search for Transiting Planets in Young Clusters Observed by K2
• The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope IV. Capabilities and predicted performance for exoplanet characterization
• Magnetic Inflation and Stellar Mass II: On the Radii of Single, Rapidly Rotating, Fully Convective M Dwarf Stars
• EvryFlare I: Long-term Evryscope Monitoring of Flares from the Cool Stars Across Half the Southern Sky
• The Impact of Stellar Rotation on the Detectability of Habitable Planets Around M Dwarfs
• Constraints on Planet Occurrence around Nearby Mid-to-Late M Dwarfs from the MEarth Project
• Red Dots: A temperate 1.5 Earth-mass planet in a compact multi-terrestrial planet system around GJ1061
• A Machine Learning Technique to Identify Transit Shaped Signals
• Diverse outcomes of planet formation and composition around low-mass stars and brown dwarfs
• HAZMAT III: The UV Evolution of Mid- to Late-M Stars with GALEX
• Two young planetary systems around field stars with ages between 20-320 Myr from TESS
• Evaluating Rotation Periods of M Dwarfs Across the Ages
• GJ1214: Rotation period, starspots, and uncertainty on the optical slope of the transmission spectrum
• The CARMENES search for exoplanets around M dwarfs. Three temperate to warm super-Earths
• Simultaneous Multiwavelength Observations of Magnetic Activity in Ultracool Dwarfs. IV. The Active, Young Binary NLTT 33370 AB (=2MASS J13142039+1320011)
• A planetary system with two transiting mini-Neptunes near the radius valley transition around the bright M dwarf TOI-776
• Recovery of TESS Stellar Rotation Periods Using Deep Learning
• Molecular Detectability in Exoplanetary Emission Spectra
• The CARMENES search for exoplanets around M dwarfs: Nine new double-line spectroscopic binary stars
• TOI-1235 b: a keystone super-Earth for testing radius valley emergence models around early M dwarfs
• TOI-811b and TOI-852b: New transiting brown dwarfs with similar masses and very different radii and ages from the TESS mission
• Discovery of a hot, transiting, Earth-sized planet and a second temperate, non-transiting planet around the M4 dwarf GJ 3473 (TOI-488)
• Calibration of the MEarth Photometric System: Optical Magnitudes and Photometric Metallicity Estimates for 1802 Nearby M-dwarfs
• The CARMENES search for exoplanets around M dwarfs. Characterization of the nearby ultra-compact multiplanetary system YZ Ceti
• EvryFlare II: Rotation Periods of the Cool Flare Stars in TESS Across Half the Southern Sky
• Four new eclipsing mid M-dwarf systems from the New Luyten Two Tenths catalog
• Photometry and Performance of SPECULOOS-South
• Bridging the gap -- the disappearance of the intermediate period gap for fully convective stars, uncovered by new ZTF rotation periods
• The beta Pictoris association: Catalog of photometric rotational periods of low-mass members and candidate members
• KELT-25b and KELT-26b: A Hot Jupiter and a Substellar Companion Transiting Young A-stars Observed by TESS
• Mass and density of the transiting hot and rocky super-Earth LHS 1478 b (TOI-1640 b)
• The CARMENES search for exoplanets around M dwarfs: The warm super-Earths in twin orbits around the mid-type M dwarfs Ross 1020 (GJ 3779) and LP 819-052 (GJ 1265)
• The beta Pictoris association low-mass members: membership assessment, rotation period distribution, and dependence on multiplicity
• The TIME Table: Rotation and Ages of Cool Exoplanet Host Stars
• Gliese 49: Activity evolution and detection of a super-Earth
• J band Variability of M Dwarfs in the WFCAM Transit Survey
• The CARMENES search for exoplanets around M dwarfs: Two Saturn-mass planets orbiting active stars
• An increased rate of large flares at intermediate rotation periods for mid-to-late M dwarfs
• The TESS Grand Unified Hot Jupiter Survey. I. Ten TESS Planets
• The CARMENES search for exoplanets around M dwarfs. Two terrestrial planets orbiting G 264-012 and one terrestrial planet orbiting Gl 393
• A Search for Additional Bodies in the GJ 1132 Planetary System from 21 Ground-based Transits and a 100 Hour Spitzer Campaign
• The CARMENES search for exoplanets around M dwarfs: Spectroscopic orbits of nine M-dwarf multiple systems, including two triples, two brown dwarf candidates, and one close M-dwarf-white dwarf binary
• Habitable Planets Eclipsing Brown Dwarfs: Strategies for Detection and Characterization
• Gliese 12 b: A temperate Earth-sized planet at 12 pc ideal for atmospheric transmission spectroscopy
• On the existence of brown dwarfs more massive than the hydrogen burning limit
• The CARMENES search for exoplanets around M dwarfs - The enigmatic planetary system GJ 4276: One eccentric planet or two planets in a 2:1 resonance?
• The Ca II H&K Rotation-Activity Relation in 53 mid-to-late type M-Dwarfs
• The Late-Type Extension to MoVeRS (LaTE-MoVeRS): Proper motion verified low-mass stars and brown dwarfs from SDSS, 2MASS, and WISE
• TOI-969: a late-K dwarf with a hot mini-Neptune in the desert and an eccentric cold Jupiter
• Exoplanet Populations and their Dependence on Host Star Properties
• Global Analysis of the TRAPPIST Ultra-Cool Dwarf Transit Survey
• Exoplanet Transits with Next-Generation Radio Telescopes
• KELT-22Ab: A Massive Hot Jupiter Transiting a Near Solar Twin
• TOI-1075 b: A Dense, Massive, Ultra-Short Period Hot Super-Earth Straddling the Radius Gap
• Kepler Observations of Very Low-Mass Stars
• A Super-Earth Orbiting Near the Inner Edge of the Habitable Zone around the M4.5-dwarf Ross 508
• A low-mass eclipsing binary within the fully convective zone from the NGTS
• Active Stars in the Spectroscopic Survey of Mid-to-Late M Dwarfs Within 15pc
• Monitoring Telluric Absorption with CAMAL
• The TEMPO Survey I: Predicting Yields of the Transiting Exosatellites, Moons, and Planets from a 30-day Survey of Orion with the Nancy Grace Roman Space Telescope
• A sensitivity analysis of the WFCAM Transit Survey for short-period giant planets around M dwarfs
• Photometric rotation periods for 107 M dwarfs from the APACHE survey
• Search for bright nearby M dwarfs with Virtual Observatory tools
• TESS discovery of a super-Earth orbiting the M dwarf star TOI-1680
• Trawling for transits in a sea of noise: A Search for Exoplanets by Analysis of WASP Optical Lightcurves and Follow-up (SEAWOLF)
• Coagulation Calculations of Icy Planet Formation Around 0.1--0.5~\msun\ Stars: Super-Earths From Large Planetestimals
• Periodic transit and variability search with simultaneous systematics filtering: Is it worth it?
• Host Star Dependence of Small Planet Mass-Radius Distributions
• EDEN Survey: Small Transiting Planet Detection Limits and Constraints on the Occurrence Rates for Late M Dwarfs within 15 pc
• Validation and atmospheric exploration of the sub-Neptune TOI-2136b around a nearby M3 dwarf
• Design Considerations for a Ground-Based Search for Transiting Planets around L and T Dwarfs
• Understanding Physical Properties of Young M-dwarfs: NIR spectroscopic studies
• HADES RV Programme with HARPS-N at TNG XIII. A sub-Neptune around the M dwarf GJ 720 A
• Planetary companions orbiting the M dwarfs GJ 724 and GJ 3988. A CARMENES and IRD collaboration
• Temporal changes of the flare activity of Proxima Cen
• Temporal Variations of Telluric Water Vapor Absorption at Apache Point Observatory
• Validation of a Third Planet in the LHS 1678 System
• Contemporaneous Observations of $H\alpha$ Luminosities and Photometric Amplitudes for M Dwarfs
• A Spitzer Search for Transits of Radial Velocity Detected Super-Earths
• A reanalysis of the LHS 1140 b atmosphere observed with the Hubble Space Telescope
• Kinematics And Ellipsoidal Motion Of The Mid To Late M-Type Stars
• Impact of Planetary Parameters on Water Clouds Microphysics
• The Featureless HST/WFC3 Transmission Spectrum of the Rocky Exoplanet GJ 1132b: No Evidence For A Cloud-Free Primordial Atmosphere and Constraints on Starspot Contamination
• The Solar Neighborhood LII: M Dwarf Twin Binaries -- Presumed Identical Twins Appear Fraternal in Variability, Rotation, H$\alpha$, and X-rays
• Sensitivity to Sub-Io-sized Exosatellite Transits in the MIRI LRS Lightcurve of the Nearest Substellar Worlds
• RedDots: Planetary masses in the GJ1061 system from planet-planet interaction
• CaII and H$\alpha$ flaring M dwarfs detected with multi-filter photometry
• Synergies between Exoplanet Surveys and Variable Star Research
• Simultaneous photometric and CARMENES spectroscopic monitoring of fast-rotating M dwarf GJ 3270. Discovery of a post-flare corotating feature
• The Solar Neighborhood. LV. M Dwarf Twin Binaries -- One in Five Twin Sibling Pairs Are Mismatched in Activity and/or Rotation
• Sibling Sub-Neptunes Around Sibling M Dwarfs: TOI-521 and TOI-912
• Activity and Rotation of Nearby Field M Dwarfs in the TESS Southern Continuous Viewing Zone