TrES-4: A Transiting Hot Jupiter of Very Low Density

Abstract

We report the discovery of TrES-4, a hot Jupiter that transits the star GSC 02620-00648 every 3.55 days. From high-resolution spectroscopy of the star we estimate a stellar effective temperature of Teff = 6100 +/- 150 K, and from high-precision z and B photometry of the transit we constrain the ratio of the semi-major axis and the stellar radius to be a/R = 6.03 +/- 0.13. We compare these values to model stellar isochrones to constrain the stellar mass to be M* = 1.22 +/- 0.17 Msun. Based on this estimate and the photometric time series, we constrain the stellar radius to be R* = 1.738 +/- 0.092 Rsun and the planet radius to be Rp = 1.674 +/- 0.094 RJup. We model our radial-velocity data assuming a circular orbit and find a planetary mass of 0.84 +/- 0.10 MJup. Our radial-velocity observations rule out line-bisector variations that would indicate a specious detection resulting from a blend of an eclipsing binary system. TrES-4 has the largest radius and lowest density of any of the known transiting planets. It presents a challenge to current models of the physical structure of hot Jupiters, and indicates that the diversity of physical properties amongst the members of this class of exoplanets has yet to be fully explored.

References in corpus (15)

• Roche lobe effects on the atmospheric loss of "Hot Jupiters"
• TrES-1: The Transiting Planet of a Bright K0V Star
• Improving Stellar and Planetary Parameters of Transiting Planet Systems: The Case of TrES-2
• Prospects for the Characterization and Confirmation of Transiting Exoplanets via the Rossiter-McLaughlin Effect
• WASP-1b and WASP-2b: Two new transiting exoplanets detected with SuperWASP and SOPHIE
• HAT-P-1b: A Large-Radius, Low-Density Exoplanet Transiting one Member of a Stellar Binary
• Using Stellar Limb-Darkening to Refine the Properties of HD 209458b
• The Transit Light Curve (TLC) Project. I. Four Consecutive Transits of the Exoplanet XO-1b
• Heat transport in giant (exo)planets: a new perspective
• Accurate fundamental parameters for Lower Main Sequence Stars
• TrES-2: The First Transiting Planet in the Kepler Field
• The Transit Light Curve Project. III. Tres Transits of TrES-1
• The Challenge of Wide-Field Transit Surveys: The Case of GSC 01944-02289
• The Transit Light Curve Project. VI. Three Transits of the Exoplanet TrES-2
• A Keck/HIRES Doppler Search for Planets Orbiting Metal-Poor Dwarfs. I. Testing Giant Planet Formation and Migration Scenarios

Cited by in corpus (40)

• Improved parameters for extrasolar transiting planets
• The Transit Light Curve Project. IX. Evidence for a Smaller Radius of the Exoplanet XO-3b
• Can TiO Explain Thermal Inversions in the Upper Atmospheres of Irradiated Giant Planets?
• The Mass of KOI-94d and a Relation for Planet Radius, Mass, and Incident Flux
• The Broadband Infrared Emission Spectrum of the Exoplanet HD 189733b
• Theoretical Spectra and Light Curves of Close-in Extrasolar Giant Planets and Comparison with Data
• Absolute properties of the low-mass eclipsing binary CM Draconis
• Tidal Heating of Extra-Solar Planets
• HAT-P-12b: A Low-Density Sub-Saturn Mass Planet Transiting a Metal-Poor K Dwarf
• WASP-4b: a 12th-magnitude transiting hot-Jupiter in the Southern hemisphere
• Homogeneous studies of transiting extrasolar planets. II. Physical properties
• Double-blind test program for astrometric planet detection with Gaia
• Extrasolar Giant Planets and X-ray Activity
• TESS Transit Timing of Hundreds of Hot Jupiters
• HAT-P-5b: A Jupiter-like hot Jupiter Transiting a Bright Star
• Constraining Orbital Parameters Through Planetary Transit Monitoring
• WASP-5b: a dense, very-hot Jupiter transiting a 12th-mag Southern-hemisphere star
• Coupled Evolution with Tides of the Radius and Orbit of Transiting Giant Planets: General Results
• The Prograde Orbit of Exoplanet TrES-2b
• WASP-7: The brightest transiting-exoplanet system in the Southern hemisphere
• ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations
• HAT-P-65b and HAT-P-66b: Two Transiting Inflated Hot Jupiters and Observational Evidence for the Re-Inflation of Close-In Giant Planets
• Atmospheric Characterization of 5 Hot Jupiters with Wide Field Camera 3 on the Hubble Space Telescope
• OGLE2-TR-L9: An extrasolar planet transiting a fast-rotating F3 star
• The composition of transiting giant extrasolar planets
• The low density transiting exoplanet WASP-15b
• The Frequency of Large Radius Hot and Very Hot Jupiters in omega Centauri
• ExoClock project II: A large-scale integrated study with 180 updated exoplanet ephemerides
• Parameters and Predictions for the Long-Period Transiting Planet HD 17156b
• Theoretical Radii of Extrasolar Giant Planets: the Cases of TrES-4, XO-3b, and HAT-P-1b
• Colour-magnitude diagrams of transiting Exoplanets - II. A larger sample from photometric distances
• Embryo impacts and gas giant mergers II: Diversity of Hot Jupiters' internal structure
• The GAPS Programme with HARPS-N@TNG VI: The Curious Case of TrES-4b
• Featureless transmission spectra of 12 giant exoplanets observed by GTC/OSIRIS
• BOWIE-ALIGN: A JWST comparative survey of aligned vs misaligned hot Jupiters to test the dependence of atmospheric composition on migration history
• SuperWASP-N Extra-solar Planet Candidates from Fields 06hr < RA < 16hr
• Photometric Orbits of Extrasolar Planets
• TOI-1438: A rare system with two short-period sub-Neptunes and a tentative long-period Jupiter-like planet orbiting a K0V star
• Observational Tests of Planet Formation Models
• Planetary Transits and Tidal Evolution