Revisiting Kepler Transiting Systems: Unvetting Planets and Constraining Relationships among Harmonics in Phase Curves

Abstract

Space-based photometric missions widely use statistical validation tools for vetting transiting planetary candidates, particularly when other traditional methods of planet confirmation are unviable. In this paper, we refute the planetary nature of three previously validated planets -- Kepler-854~b, Kepler-840~b, and Kepler-699~b -- and possibly a fourth, Kepler-747~b, using updated stellar parameters from Gaia and phase-curve analysis. In all four cases, the inferred physical radii rule out their planetary nature given the stellar radiation the companions receive. For Kepler-854~b, the mass derived from the host star's ellipsoidal variation, which had not been part of the original vetting procedure, similarly points to a non-planetary value. To contextualize our understanding of the phase curve for stellar mass companions in particular and extend our understanding of high-order harmonics, we examine Kepler eclipsing binaries with periods between 1.5 and 10 days. Using a sample of 20 systems, we report a strong power-law relation between the second cosine harmonic of the phase-curve signal and the higher cosine harmonics, which supports the hypothesis that those signals arise from the tidal interaction between the binary components. We find that the ratio between the second and third-harmonic amplitudes is $2.24\pm 0.48$, in good agreement with the expected value of 2.4 from the classical formalism for the ellipsoidal distortion.

References in corpus (68)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• Gaia Data Release 2. Summary of the contents and survey properties
• A new extensive library of PHOENIX stellar atmospheres and synthetic spectra
• The K2 Mission: Characterization and Early results
• The Revised TESS Input Catalog and Candidate Target List
• Kepler Input Catalog: Photometric Calibration and Stellar Classification
• The CoRoT satellite in flight : description and performance
• Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves
• Overview of the Kepler Science Processing Pipeline
• Probabilistic Forecasting of the Masses and Radii of Other Worlds
• Kepler Eclipsing Binary Stars. I. Catalog and Principal Characterization of 1879 Eclipsing Binaries in the First Data Release
• False positive probabilties for all Kepler Objects of Interest: 1284 newly validated planets and 428 likely false positives
• Kepler Eclipsing Binary Stars. VII. The Catalog of Eclipsing Binaries Found in the Entire Kepler Data-Set
• The TESS Objects of Interest Catalog from the TESS Prime Mission
• The Statistics of Albedo and Heat Recirculation on Hot Exoplanets
• Binning is sinning: morphological light-curve distortions due to finite integration time
• Inference of Inhomogeneous Clouds in an Exoplanet Atmosphere
• An Efficient Automated Validation Procedure for Exoplanet Transit Candidates
• Modeling Kepler transit light curves as false positives: Rejection of blend scenarios for Kepler-9, and validation of Kepler-9d, a super-Earth-size planet in a multiple system
• Lack of Inflated Radii for Kepler Giant Planet Candidates Receiving Modest Stellar Irradiation
• On the Low False Positive Probabilities of Kepler Planet Candidates
• Periodic Flux Variability of Stars due to the Reflex Doppler Effect Induced by Planetary Companions
• 197 Candidates and 104 Validated Planets in K2's First Five Fields
• PASTIS: Bayesian extrasolar planet validation. I. General framework, models, and performance
• Changing Phases of Alien Worlds: Probing Atmospheres of Kepler Planets with High-Precision Photometry
• Photometric detection of non-transiting short-period low-mass companions through the beaming, ellipsoidal and reflection effects in Kepler and CoRoT lightcurves
• Stellar and Planetary Properties of K2 Campaign 1 Candidates and Validation of 17 Planets, Including a Planet Receiving Earth-like Insolation
• Atmospheric Circulation of Hot Jupiters: A Shallow Three-Dimensional Model
• Kepler Eclipsing Binary Stars. IV. Precise Eclipse Times for Close Binaries and Identification of Candidate Three-Body Systems
• 275 Candidates and 149 Validated Planets Orbiting Bright Stars in K2 Campaigns 0-10
• Vetting of 384 TESS Objects of Interest with TRICERATOPS and Statistical Validation of 12 Planet Candidates
• A Kepler Study of Starspot Lifetimes with Respect to Light Curve Amplitude and Spectral Type
• Transits and Occultations of an Earth-Sized Planet in an 8.5-Hour Orbit
• ELLC - a fast, flexible light curve model for detached eclipsing binary stars and transiting exoplanets
• A comprehensive study of Kepler phase curves and secondary eclipses -- temperatures and albedos of confirmed Kepler giant planets
• The Transit Light Source Effect II: The Impact of Stellar Heterogeneity on Transmission Spectra of Planets Orbiting Broadly Sun-like Stars
• Validation of Twelve Small Kepler Transiting Planets in the Habitable Zone
• Atmospheric Characterization of the Hot Jupiter Kepler-13Ab
• KOI 1224, a Fourth Bloated Hot White Dwarf Companion Found With Kepler
• Variability in the Atmosphere of the Hot Giant Planet HAT-P-7 b
• Detection Of KOI-13.01 Using The Photometric Orbit
• Ellipsoidal Oscillations Induced by Substellar Companions: A Prospect for the Kepler Mission
• NGTS-1b: A hot Jupiter transiting an M-dwarf
• Studying atmosphere-dominated hot Jupiter Kepler phase curves: Evidence that inhomogeneous atmospheric reflection is common
• The astrophysics of visible-light orbital phase curves in the space age
• A ground-based measurement of the relativistic beaming effect in a detached double WD binary
• Investigating hot-Jupiter inflated radii with hierarchical Bayesian modelling
• 44 Validated Planets from K2 Campaign 10
• TESS spots a hot Jupiter with an inner transiting Neptune
• Systematic Phase Curve Study of Known Transiting Systems from Year 1 of the TESS Mission
• Kepler Observations of Transiting Hot Compact Objects
• Visible-light Phase Curves from the Second Year of the TESS Primary Mission
• Confirmation of Hot Jupiter Kepler-41b via Phase Curve Analysis
• Discovery of Two New Thermally Bloated Low-Mass White Dwarfs Among the Kepler Binaries
• BEER analysis of Kepler and CoRoT light curves: IV. Discovery of four new low-mass white dwarf companions in the Kepler data
• Search for Dormant Black Holes in Ellipsoidal Variables I. Revisiting the Expected Amplitudes of the Photometric Modulation
• 37 New Validated Planets in Overlapping K2 Campaigns
• Validation of small Kepler transiting planet candidates in or near the habitable zone
• Three statistically validated K2 transiting warm Jupiter exoplanets confirmed as low-mass stars
• Reflected Light Curves, Spherical and Bond Albedos of Jupiter- and Saturn-like Exoplanets
• High Order Harmonics in Light Curves of Kepler Planets
• Kepler-447b: a hot-Jupiter with an extremely grazing transit
• Odd Harmonics in Exoplanet Photometry: Weather or Artifact?
• Supervised Learning Detection of Sixty Non-Transiting Hot Jupiter Candidates
• The full $Kepler$ phase curve of the eclipsing hot white dwarf binary system KOI-964
• Discovery of Six Optical Phase Curves with K2

Cited by in corpus (2)

• Multiplicity Boost Of Transit Signal Classifiers: Validation of 69 New Exoplanets Using The Multiplicity Boost of ExoMiner
• Is binning always sinning? The impact of time-averaging for exoplanet phase curves