The Orbit of WASP-12b is Decaying

Abstract

WASP-12b is a transiting hot Jupiter on a 1.09-day orbit around a late-F star. Since the planet's discovery in 2008, the time interval between transits has been decreasing by $29\pm 2$ msec year${}^{-1}$. This is a possible sign of orbital decay, although the previously available data left open the possibility that the planet's orbit is slightly eccentric and is undergoing apsidal precession. Here, we present new transit and occultation observations that provide more decisive evidence for orbital decay, which is favored over apsidal precession by a $\Delta \mathrm{BIC}$ of 22.3 or Bayes factor of 70,000. We also present new radial-velocity data that rule out the Rømer effect as the cause of the period change. This makes WASP-12 the first planetary system for which we can be confident that the orbit is decaying. The decay timescale for the orbit is $P/\dot{P}=3.25\pm 0.23$ Myr. Interpreting the decay as the result of tidal dissipation, the modified stellar tidal quality factor is $Q_{\star }^{\prime }=1.8\times 10^5$.

arXiv comment16 pages, 6 tables, 5 figures, accepted to AJ

References in corpus (73)

• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• The NumPy array: a structure for efficient numerical computation
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Analytic Lightcurves for Planetary Transit Searches
• batman: BAsic Transit Model cAlculatioN in Python
• EXOFAST: A fast exoplanetary fitting suite in IDL
• RadVel: The Radial Velocity Modeling Toolkit
• Tidal dissipation in stars and giant planets
• The California Planet Survey I. Four New Giant Exoplanets
• Tidal Decay of Close Planetary Orbits
• WASP-12b: The hottest transiting planet yet discovered
• Tidal Evolution of Close-in Extra-Solar Planets
• The GAPS Programme with HARPS-N@TNG XIV. Investigating giant planet migration history via improved eccentricity and mass determination for 231 transiting planets
• Friends of Hot Jupiters I: A Radial Velocity Search for Massive, Long-Period Companions to Close-In Gas Giant Planets
• Metals in the Exosphere of the Highly Irradiated Planet WASP-12b
• A Robust Measure of Tidal Circularization in Coeval Binary Populations: The solar-type spectroscopic Binary Population in The Open Cluster M35
• Orbital perturbations on transiting planets: A possible method to measure stellar quadrupoles and to detect Earth-mass planets
• Spitzer Secondary Eclipses of the Dense, Modestly-irradiated, Giant Exoplanet HAT-P-20b Using Pixel-Level Decorrelation
• Kepler constraints on planets near hot Jupiters
• EVEREST: Pixel Level Decorrelation of K2 Light curves
• Near-UV Absorption, Chromospheric Activity, and Star-Planet Interactions in the WASP-12 system
• Probing the Interiors of Very Hot Jupiters Using Transit Light Curves
• Warm Jupiters are less lonely than hot Jupiters: close neighbours
• Thermal Phase Variations of WASP-12b: Defying Predictions
• The Apparently Decaying Orbit of WASP-12
• Transmission Spectroscopy of the Hot-Jupiter WASP-12b from 0.7 to 5 microns
• Falling Transiting Extrasolar Giant Planets
• Departure from the constant-period ephemeris for the transiting exoplanet WASP-12 b
• On the Orbit of Exoplanet WASP-12b
• WASP-12b as a prolate, inflated and disrupting planet from tidal dissipation
• Re-Evaluating WASP-12b: Strong Emission at 2.315 micron, Deeper Occultations, and an Isothermal Atmosphere
• The Roche limit for close-orbiting planets: Minimum density, composition constraints, and application to the 4.2-hour planet KOI 1843.03
• Mass Transfer, Transiting Stream and Magnetopause in Close-in Exoplanetary Systems with Applications to WASP-12
• Orbital decay of hot Jupiters due to nonlinear tidal dissipation within solar-type hosts
• The High Eccentricity of the Planet Around 16 Cyg B
• Hot Jupiters are Destroyed by Tides While Their Host Stars are on the Main Sequence
• Constraining Tidal Dissipation in Stars from The Destruction Rates of Exoplanets
• Observational constraints on tidal effects using orbital eccentricities
• Empirical Tidal Dissipation in Exoplanet Hosts From Tidal Spin-Up
• The New Transiting Planet OGLE-TR-56b: Orbit and Atmosphere
• Observability of the General Relativistic Precession of Periastra in Exoplanets
• Extrasolar Planet Transits Observed at Kitt Peak National Observatory
• Towards Space-like Photometric Precision from the Ground with Beam-Shaping Diffusers
• The Transit Light Curve project. XIV. Confirmation of Anomalous Radii for the Exoplanets TrES-4b, HAT-P-3b, and WASP-12b
• Transit Timing Variation Measurements of WASP-12b and Qatar-1b: No Evidence for Additional Planets
• Tidally-driven Roche-Lobe Overflow of Hot Jupiters with MESA
• Hierarchical Bayesian calibration of tidal orbit decay rates among hot Jupiters
• Periastron Precession Measurements in Transiting Extrasolar Planetary Systems at the Level of General Relativity
• Mass Loss from the Exoplanet WASP-12b Inferred from $\text{Spitzer}$ Phase Curves
• Diffuser-Assisted Infrared Transit Photometry for Four Dynamically Interacting \textit{Kepler} Systems
• Near-infrared Thermal Emission Detections of a number of hot Jupiters and the Systematics of Ground-based Near-infrared Photometry
• Tidal Dissipation in WASP-12
• Hubble Space Telescope observations of the NUV transit of WASP-12b
• Understanding WASP-12b
• Multi-site campaign for transit timing variations of WASP-12 b: possible detection of a long-period signal of planetary origin
• A New Model of Roche-lobe Overflow for Short-Period Gaseous Planets and Binary Stars
• Tidal Decay and Stable Roche-Lobe Overflow of Short-Period Gaseous Exoplanets
• High-precision photometry of WASP-12 b transits
• Homogeneously derived transit timings for 17 exoplanets and reassessed TTV trends for WASP-12 and WASP-4
• Orbital eccentricity of WASP-12 and WASP-14 from new radial-velocity monitoring with SOPHIE
• An estimate of the $k_2$ Love number of WASP-18Ab from its radial velocity measurements
• Obliquity Tides May Drive WASP-12b's Rapid Orbital Decay
• Transmission photometry of WASP-12b: simultaneous measurement of the planetary radius in three bands
• The Radial Velocity Signature of Tides Raised in Stars Hosting Exoplanets
• ULTRACAM z'-band Detection of the Secondary Eclipse of WASP-12b
• WIRC+Pol: a low-resolution near-infrared spectropolarimeter
• Planets on the Edge
• First Light of Engineered Diffusers at the Nordic Optical Telescope Reveal Time Variability in the Optical Eclipse Depth of WASP-12b
• Discarding orbital decay in WASP-19b after one decade of transit observations
• Instability of mass transfer in a planet-star system
• Storms or Systematics? The changing secondary eclipse depth of WASP-12b
• WASP-12b: A Mass-Losing Extremely Hot Jupiter

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