Physical properties of the WASP-44 planetary system from simultaneous multi-colour photometry

Abstract

We present ground-based broad-band photometry of two transits in the WASP-44 planetary system obtained simultaneously through four optical (Sloan g', r', i', z') and three near-infrared (NIR; J, H, K) filters. We achieved low scatters of 1-2 mmag per observation in the optical bands with a cadence of 48 s, but the NIR-band light curves present much greater scatter. We also observed another transit of WASP-44 b by using a Gunn-r filter and telescope defocussing, with a scatter of 0.37 mmag per point and an observing cadence around 135 s. We used these data to improve measurements of the time of mid-transit and the physical properties of the system. In particular, we improved the radius measurements of the star and planet by factors of 3 and 4, respectively. We find that the radius of WASP-44 b is 1.002 R_Jup, which is slightly smaller than previously thought and differs from that expected for a core-free planet. In addition, with the help of a synthetic spectrum, we investigated the theoretically-predicted variation of the planetary radius as a function of wavelength, covering the range 370-2440 nm. We can rule out extreme variations at optical wavelengths, but unfortunately our data are not precise enough (especially in the NIR bands) to differentiate between the theoretical spectrum and a radius which does not change with wavelength.

13 pages, 6 figures, to appear in Monthly Notices of the Royal Astronomical Society

References in corpus (97)

• Detection of an Extrasolar Planet Atmosphere
• Planetary Candidates Observed by Kepler, III: Analysis of the First 16 Months of Data
• Characteristics of planetary candidates observed by Kepler, II: Analysis of the first four months of data
• Planetary Radii across Five Orders of Magnitude in Mass and Stellar Insolation: Application to Transits
• Achieving better than 1 minute accuracy in the Heliocentric and Barycentric Julian Dates
• On the Unique Solution of Planet and Star Parameters from an Extrasolar Planet Transit Light Curve
• The orbital motion, absolute mass, and high-altitude winds of exoplanet HD209458b
• A Unified Theory for the Atmospheres of the Hot and Very Hot Jupiters: Two Classes of Irradiated Atmospheres
• A map of the day-night contrast of the extrasolar planet HD 189733b
• Theoretical Transmission Spectra During Extrasolar Giant Planet Transits
• Detection of oxygen and carbon in the hydrodynamically escaping atmosphere of the extrasolar planet HD209458b
• Detection of Thermal Emission from an Extrasolar Planet
• The effect of red noise on planetary transit detection
• Homogeneous studies of transiting extrasolar planets. IV. Thirty systems with space-based light curves
• Detection of atmospheric haze on an extrasolar planet: The 0.55 - 1.05 micron transmission spectrum of HD189733b with the Hubble Space Telescope
• Sodium Absorption From the Exoplanetary Atmosphere of HD189733b Detected in the Optical Transmission Spectrum
• Hubble Space Telescope Transmission Spectroscopy of the Exoplanet HD 189733b: High-altitude atmospheric haze in the optical and near-UV with STIS
• Transmission Spectra as Diagnostics of Extrasolar Giant Planet Atmospheres
• GROND - a 7-channel imager
• Possible Solutions to the Radius Anomalies of Transiting Giant Planets
• Homogeneous studies of transiting extrasolar planets. I. Light curve analyses
• Characteristics of Kepler Planetary Candidates Based on the First Data Set: The Majority are Found to be Neptune-Size and Smaller
• Measurement of Spin-Orbit Alignment in an Extrasolar Planetary System
• Albedo and Reflection Spectra of Extrasolar Giant Planets
• Metals in the Exosphere of the Highly Irradiated Planet WASP-12b
• 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?
• Transmission Spectra of Three-Dimensional Hot Jupiter Model Atmospheres
• Atmospheric Sulfur Photochemistry on Hot Jupiters
• Homogeneous studies of transiting extrasolar planets. III. Additional planets and stellar models
• KELT-1b: A Strongly Irradiated, Highly Inflated, Short Period, 27 Jupiter-mass Companion Transiting a mid-F Star
• On the Radii of Extrasolar Giant Planets
• Theoretical Spectra and Atmospheres of Extrasolar Giant Planets
• Comparative Planetary Atmospheres: Models of TrES-1 and HD209458b
• Ground-based detection of sodium in the transmission spectrum of exoplanet HD209458b
• Using Stellar Limb-Darkening to Refine the Properties of HD 209458b
• The Heavy Element Masses of Extrasolar Giant Planets, Revealed
• Lack of Inflated Radii for Kepler Giant Planet Candidates Receiving Modest Stellar Irradiation
• Theory of Extrasolar Giant Planet Transits
• A Spectrum of an Extrasolar Planet
• High-precision photometry by telescope defocussing. I. The transiting planetary system WASP-5
• The Optical and Near-Infrared Transmission Spectrum of the Super-Earth GJ1214b: Further Evidence for a Metal-Rich Atmosphere
• On the Anomalous Radii of the Transiting Extrasolar Planets
• HST/STIS Optical Transit Transmission Spectra of the hot-Jupiter HD209458b
• Tidal Heating of Extra-Solar Planets
• Identification of Absorption Features in an Extrasolar Planet Atmosphere
• A new look at NICMOS transmission spectroscopy of HD189733, GJ-436 and XO-1: no conclusive evidence for molecular features
• Atmospheric Dynamics of Short-period Extra Solar Gas Giant Planets I: Dependence of Night-Side Temperature on Opacity
• Seven transiting hot-Jupiters from WASP-South, Euler and TRAPPIST: WASP-47b, WASP-55b, WASP-61b, WASP-62b, WASP-63b, WASP-66b & WASP-67b
• Eclipsing binaries as standard candles: HD 23642 and the distance to the Pleiades
• Homogeneous studies of transiting extrasolar planets. V. New results for 38 planets
• Gran Telescopio Canarias OSIRIS Transiting Exoplanet Atmospheric Survey: Detection of potassium in XO-2b from narrowband spectrophotometry
• TiO and VO broad band absorption features in the optical spectrum of the atmosphere of the hot-Jupiter HD209458b
• Probing the terminator region atmosphere of the Hot-Jupiter XO-1b with transmission spectroscopy
• Probing the haze in the atmosphere of HD 189733b with HST/WFC3 transmission spectroscopy
• A Gemini ground-based transmission spectrum of WASP-29b: a featureless spectrum from 515 to 720nm
• Homogeneous studies of transiting extrasolar planets. II. Physical properties
• HAT-P-39b--HAT-P-41b: Three Highly Inflated Transiting Hot Jupiters
• Inflating and Deflating Hot Jupiters: Coupled Tidal and Thermal Evolution of Known Transiting Planets
• A method for the direct determination of the surface gravities of transiting extrasolar planets
• Photometric and Spectral Signatures of 3D Models of Transiting Giant Exoplanets
• Determining atmospheric conditions at the terminator of the hot-Jupiter HD209458b
• Rayleigh scattering by H2 in the extrasolar planet HD209458b
• High accuracy transit photometry of the planet OGLE-TR-113b with a new deconvolution-based method
• The Transit Light Curve Project. VII. The Not-So-Bloated Exoplanet HAT-P-1b
• GTC OSIRIS transiting exoplanet atmospheric survey: detection of sodium in XO-2b from differential long-slit spectroscopy
• Methane in the atmosphere of the transiting hot Neptune GJ436b?
• Improved precision on the radius of the nearby super-Earth 55 Cnc e
• Determination of the Interior Structure of Transiting Planets in Multiple-Planet Systems
• High Resolution, Differential, Near-infrared Transmission Spectroscopy of GJ 1214b
• Water in HD 209458b's atmosphere from 3.6 - 8 microns IRAC photometric observations in primary transit
• WASP-44b, WASP-45b and WASP-46b: three short-period, transiting extrasolar planets
• The Transit Light Curve Project. XI. Submillimagnitude Photometry of Two Transits of the Bloated Planet WASP-4b
• Optical to near-infrared transit observations of super-Earth GJ1214b: water-world or mini-Neptune?
• A new Search for Carbon Monoxide Absorption in the Transmission Spectrum of the Extrasolar Planet HD 209458b
• Primary transit of the planet HD189733b at 3.6 and 5.8 microns
• HAT-P-34b -- HAT-P-37b: Four Transiting Planets More Massive Than Jupiter Orbiting Moderately Bright Stars
• HATS-1b: The First Transiting Planet Discovered by the HATSouth Survey
• Spitzer/MIPS 24 micron Observations of HD 209458b: 3 eclipses, 2.5 transits, and a Phase Curve Corrupted by Instrumental Sensitivity Variations
• Coupled Evolution with Tides of the Radius and Orbit of Transiting Giant Planets: General Results
• Transmission spectroscopy of the sodium 'D' doublet in WASP-17b with the VLT
• Updated parameters for the transiting exoplanet WASP-3b using RISE, a new fast camera for the Liverpool Telescope
• WASP-78b and WASP-79b: Two highly-bloated hot Jupiter-mass exoplanets orbiting F-type stars in Eridanus
• Tidal Heating Models for the Radii of the Inflated Transiting Giant Planets WASP-4b, WASP-6b, WASP-12b, and TrES-4
• KELT-2Ab: A Hot Jupiter Transiting the Bright (V=8.77) Primary Star of a Binary System
• A lower radius and mass for the transiting extrasolar planet HAT-P-8b
• Qatar-2: A K dwarf orbited by a transiting hot Jupiter and a more massive companion in an outer orbit
• Physical properties and radius variations in the HAT-P-5 planetary system from simultaneous four-colour photometry
• A Spitzer Infrared Radius for the Transiting Extrasolar Planet HD209458b
• Transmission spectroscopy of exoplanet XO-2b observed with HST NICMOS
• The Internal Structural Adjustment due to Tidal Heating of Short-Period Inflated Giant Planets
• Transit spectrophotometry of the exoplanet HD189733b. II. New Spitzer observations at 3.6 microns
• Error estimation in astronomy: A guide
• Refined physical properties of the HAT-P-13 planetary system
• On the Size Distribution of Close-In Extrasolar Giant Planets
• Probing potassium in the atmosphere of HD 80606b with tunable filter transit spectrophotometry from the Gran Telescopio Canarias
• WASP-4b Transit Observations With GROND

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• Ground-based near-UV observations of 15 transiting exoplanets: Constraints on their atmospheres and no evidence for asymmetrical transits
• WASP-80b has a dayside within the T-dwarf range
• TESS Transit Timing of Hundreds of Hot Jupiters
• Physical properties, transmission and emission spectra of the WASP-19 planetary system from multi-colour photometry
• ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations
• HATS-3b: An inflated hot Jupiter transiting an F-type star
• Orbital alignment and starspot properties in the WASP-52 planetary system
• Optical-to-Near-Infrared Simultaneous Observations for the Hot Uranus GJ3470b: A Hint for Cloud-free Atmosphere
• Discrepancies between isochrone fitting and gyrochronology for exoplanet host stars?
• High-precision photometry by telescope defocussing. VII. The ultra-short period planet WASP-103
• Physical properties, starspot activity, orbital obliquity, and transmission spectrum of the Qatar-2 planetary system from multi-colour photometry
• Broad-band transmission spectrum and K-band thermal emission of WASP-43b as observed from the ground
• Broad-band spectrophotometry of the hot Jupiter HAT-P-12b from the near-UV to the near-IR
• ExoClock project II: A large-scale integrated study with 180 updated exoplanet ephemerides
• Physical properties and transmission spectrum of the WASP-80 planetary system from multi-colour photometry
• Simultaneous follow-up of planetary transits: revised physical properties for the planetary systems HAT-P-16 and WASP-21
• Physical properties of the WASP-67 planetary system from multi-colour photometry
• High-precision photometry by telescope defocussing. V. WASP-15 and WASP-16
• Physical properties of the HAT-P-23 and WASP-48 planetary systems from multi-colour photometry
• Possible detection of a bimodal cloud distribution in the atmosphere of HAT-P-32\,A\,b from multi-band photometry
• The ultra-hot-Jupiter KELT-16 b: Dynamical Evolution and Atmospheric Properties
• Looking For Timing Variations in the Transits of 16 Exoplanets
• Multi-band characterization of the hot Jupiters: WASP-5b, WASP-44b and WASP-46b
• The benefit of simultaneous seven-filter imaging: 10 years of GROND observations
• Simulations of starspot anomalies within TESS exoplanetary transit light curves -- II
• SIOUX project: a simultaneous multiband camera for exoplanet atmospheres studies