HAT-P-1b: A Large-Radius, Low-Density Exoplanet Transiting one Member of a Stellar Binary

Abstract

Using small automated telescopes in Arizona and Hawaii, the HATNet project has detected an object transiting one member of the double star system ADS 16402 AB. This system is a pair of G0 main-sequence stars with age about 3 Gyr at a distance of ~139 pc and projected separation of ~1550 AU. The transit signal has a period of 4.46529 days and depth of 0.015 mag. From follow-up photometry and spectroscopy, we find that the object is a "hot Jupiter" planet with mass about 0.53 M_jup and radius ~1.36 R_jup traveling in an orbit with semimajor axis 0.055 AU and inclination about 85.9 deg, thus transiting the star at impact parameter 0.74 of the stellar radius. Based on a data set spanning three years, ephemerides for the transit center are: T_C = 2453984.397 + N_tr * 4.46529. The planet, designated HAT-P-1b, appears to be at least as large in radius, and smaller in mean density, than any previously-known planet.

8 pages, accepted for publication in ApJ, see also http://www.hatnet.hu (www.hatnet.hu)

References in corpus (8)

• TrES-1: The Transiting Planet of a Bright K0V Star
• 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
• TrES-2: The First Transiting Planet in the Kepler Field
• A Transiting Planet of a Sun-like Star
• A stellar companion in the HD 189733 system with a known transiting extrasolar planet
• Transit Photometry of the Core-Dominated Planet HD 149026b
• The N2K Consortium VI: Doppler Shifts Without Templates and Three New Short-Period Planets

Cited by in corpus (75)

• Improved parameters for extrasolar transiting planets
• Homogeneous studies of transiting extrasolar planets. I. Light curve analyses
• Efficient identification of exoplanetary transit candidates from SuperWASP light curves
• The Mass of KOI-94d and a Relation for Planet Radius, Mass, and Incident Flux
• Theoretical Spectra and Light Curves of Close-in Extrasolar Giant Planets and Comparison with Data
• Tau-REx I: A next generation retrieval code for exoplanetary atmospheres
• HD147506b: A Super-Massive Planet in an Eccentric Orbit Transiting a Bright Star
• Long-term tidal evolution of short-period planets with companions
• Towards Closing the Window on Strongly Interacting Dark Matter: Far-Reaching Constraints from Earth's Heat Flow
• The Transit Light Curve Project. V. System Parameters and Stellar Rotation Period of HD 189733
• Tidal Heating of Extra-Solar Planets
• XO-2b: Transiting Hot Jupiter in a Metal-rich Common Proper Motion Binary
• Homogeneous studies of transiting extrasolar planets. II. Physical properties
• A method for the direct determination of the surface gravities of transiting extrasolar planets
• Observational Evidence for Tidal Interaction in Close Binary Systems
• Instrumentation for the detection and characterization of exoplanets
• The Transit Light Curve Project. III. Tres Transits of TrES-1
• TrES-4: A Transiting Hot Jupiter of Very Low Density
• The Transit Light Curve Project. VII. The Not-So-Bloated Exoplanet HAT-P-1b
• A Smaller Radius for the Transiting Exoplanet WASP-10b
• TESS Transit Timing of Hundreds of Hot Jupiters
• KELT-20b: A giant planet with a period of P~ 3.5 days transiting the V~ 7.6 early A star HD 185603
• The multiplicity of exoplanet host stars - New low-mass stellar companions of the exoplanet host stars HD125612 and HD212301
• SOPHIE velocimetry of Kepler transit candidates XII. KOI-1257 b: a highly eccentric three-month period transiting exoplanet
• High precision abundances in the 16 Cyg binary system: a signature of the rocky core in the giant planet
• Coupled Evolution with Tides of the Radius and Orbit of Transiting Giant Planets: General Results
• A high precision chemical abundance analysis of the HAT-P-1 stellar binary: constraints on planet formation
• Analysis of Early Science observations with the CHaracterising ExOPlanets Satellite (CHEOPS) using pycheops
• Low False-Positive Rate of Kepler Candidates Estimated From A Combination Of Spitzer And Follow-Up Observations
• An Improbable Solution to the Underluminosity of 2M1207B: A Hot Protoplanet Collision Afterglow
• Predicting the Yields of Photometric Surveys for Transiting Extrasolar Planets
• WASP-94 A and B planets: hot-Jupiter cousins in a twin-star system
• The composition of transiting giant extrasolar planets
• Solar System Physics for Exoplanet Research
• The Frequency of Large Radius Hot and Very Hot Jupiters in omega Centauri
• First limits on the occurrence rate of short-period planets orbiting brown dwarfs
• WASP-1: A lithium- and metal-rich star with an oversized planet
• KELT-19Ab: A P~4.6 Day Hot Jupiter Transiting a Likely Am Star with a Distant Stellar Companion
• Deep MMT Transit Survey of the Open Cluster M37 IV: Limit on the Fraction of Stars With Planets as Small as 0.3 R_J
• Theoretical Radii of Extrasolar Giant Planets: the Cases of TrES-4, XO-3b, and HAT-P-1b
• A Photometric Survey for Variables and Transits in the Field of Praesepe with KELT
• GTC OSIRIS transiting exoplanet atmospheric survey: detection of potassium in HAT-P-1b from narrowband spectrophotometry
• Colour-magnitude diagrams of transiting Exoplanets - II. A larger sample from photometric distances
• Millimagnitude Photometry for Transiting Extrasolar Planetary Candidates: II. Transits of OGLE-TR-113-b in the Optical and Near-IR
• De-Trending Time Series for Astronomical Variability Surveys
• Multi-filter transit observations of WASP-39b and WASP-43b with three San Pedro Mártir telescopes
• An Information-Theoretic Approach to Optimize JWST Observations and Retrievals of Transiting Exoplanet Atmospheres
• The Dynamics-Based Approach to Studying Terrestrial Exoplanets
• Photometric follow-up of the transiting planet WASP-1b
• Transit and Radial Velocity Survey Efficiency Comparison for a Habitable Zone Earth
• The Lupus Transit Survey For Hot Jupiters: Results and Lessons
• Detectability of Exoplanetary Transits from Radial Velocity Surveys
• A search for transiting extrasolar planet candidates in the OGLE-II microlens database of the galactic plane
• Exoplanet Interior Retrievals: core masses and metallicities from atmospheric abundances
• Three long period transiting giant planets from TESS
• SuperWASP-North Extra-solar Planet Candidates between 3hr < RA < 6hr
• HD 75289Ab revisited - Searching for starlight reflected from a hot Jupiter
• Observational Window Functions in Planet Transit Surveys
• On constraining a transiting exoplanet's rotation rate with its transit spectrum
• Investigation of transit-selected exoplanet candidates from the MACHO survey
• A Ground-Based Search for Thermal Emission from the Exoplanet TrES-1
• Accurate Atmospheric Parameters at Moderate Resolution Using Spectral Indices: Preliminary Application to the MARVELS Survey
• Detecting "Temperate" Jupiters: The Prospects of Searching for Transiting Gas Giants in Habitability Zones
• Detection of Na and K in the atmosphere of the hot Jupiter HAT-P-1b with P200/DBSP
• Looking For Timing Variations in the Transits of 16 Exoplanets
• A Population Analysis of 20 Exoplanets Observed from the Optical to the Near-infrared Wavelengths with HST: Evidence for Widespread Stellar Contamination
• Spectroscopic Transit Search: a self-calibrating method for detecting planets around bright stars
• A Possible Mechanism for Driving Oscillations in Hot Giant Planets
• Planet Hunters NGTS: New Planet Candidates from a Citizen Science Search of the Next Generation Transit Survey Public Data
• Exoplanet Nodal Precession Induced by Rapidly Rotating Stars: Impacts on Transit Probabilities and Biases
• Spectral types of planetary host star candidates from OGLE III
• Planetary Transits and Tidal Evolution
• The Life Cycle of an XO Planet and the Potential to Detect Transiting Planets of M Dwarfs
• Evidence for the Late Arrival of Hot Jupiters in Systems with High Host-star Obliquities
• Revisiting BD-06 1339b: A Likely False Positive Caused by Stellar Activity