TASTE IV. Refining ephemeris and orbital parameters for HAT-P-20b and WASP-1b

Abstract

We present four new light curves of transiting exoplanets WASP-1b and HAT-P-20b, observed within the TASTE (The Asiago Search for Transit timing variations of Exoplanets) project. We re-analyzed light curves from the literature in a homogeneous way, calculating a refined ephemeris and orbital-physical parameters for both objects. WASP-1b does not show any significant Transit Timing Variation signal at the 120 s-level. As for HAT-P-20b, we detected a deviation from our re-estimated linear ephemeris that could be ascribed to the presence of a perturber or, more probably, to a previously unnoticed high level of stellar activity. The rotational period of HAT-P-20 A we obtained from archival data (P_rot ~ 14.5 days), combined with its optical variability and strong emission of CaII H&K lines, is consistent with a young stellar age (< 1 Gyr) and support the hypothesis that stellar activity may be responsible of the measured deviations of the transit times.

arXiv comment7 pages, 4 figures, 3 tables, accepted to Astronomische Nachrichten

References in corpus (25)

• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• The WASP Project and the SuperWASP Cameras
• Astrometry.net: Blind astrometric calibration of arbitrary astronomical images
• Achieving better than 1 minute accuracy in the Heliocentric and Barycentric Julian Dates
• On detecting terrestrial planets with timing of giant planet transits
• DHP Framework: Digital Health Passports Using Blockchain -- Use case on international tourism during the COVID-19 pandemic
• Hot Stars with Hot Jupiters Have High Obliquities
• Eclipsing binaries in open clusters. II. V453 Cyg in NGC 6871
• The first WASP public data release
• Homogeneous studies of transiting extrasolar planets. III. Additional planets and stellar models
• WASP-1b and WASP-2b: Two new transiting exoplanets detected with SuperWASP and SOPHIE
• Rotation Periods, Variability Properties and Ages for Kepler Exoplanet Candidate Host Stars
• Stellar rotation in the Hyades and Praesepe: gyrochronology and braking timescale
• HAT-P-20b--HAT-P-23b: Four Massive Transiting Extrasolar Planets
• Effect of stellar spots on high-precision transit light-curve
• Deep MMT Transit Survey of the Open Cluster M37 II: Variable Stars
• Transit timing variations in WASP-10b induced by stellar activity?
• Multiwavelength flux variations induced by stellar magnetic activity: effects on planetary transits
• Precise Radius Estimates for the Exoplanets WASP-1b and WASP-2b
• Multiple planets or exomoons in Kepler hot Jupiter systems with transit timing variations?
• TASTE: The Asiago Search for Transit timing variations of Exoplanets. I. Overview and improved parameters for HAT-P-3b and HAT-P-14b
• HAT-P-13: a multi-site campaign to detect the transit of the second planet in the system
• TASTE. III. A homogeneous study of transit time variations in WASP-3b
• Photometric follow-up of the transiting planet WASP-1b
• TASTE. II. A new observational study of transit time variations in HAT-P-13b

Cited by in corpus (12)

• Spitzer Secondary Eclipses of the Dense, Modestly-irradiated, Giant Exoplanet HAT-P-20b Using Pixel-Level Decorrelation
• Ground-based near-UV observations of 15 transiting exoplanets: Constraints on their atmospheres and no evidence for asymmetrical transits
• TESS Transit Timing of Hundreds of Hot Jupiters
• ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations
• The GAPS Programme with HARPS-N at TNG. XIII. The orbital obliquity of three close-in massive planets hosted by dwarf K-type stars: WASP-43, HAT-P-20 and Qatar-2
• ExoClock project II: A large-scale integrated study with 180 updated exoplanet ephemerides
• ExoClock Project: An open platform for monitoring the ephemerides of Ariel targets with contributions from the public
• The TROY project: II. Multi-technique constraints on exotrojans in nine planetary systems
• Does magnetic field impact tidal dynamics inside the convective zone of low-mass stars along their evolution?
• TASTE V. A new ground-based investigation of orbital decay in the ultra-hot Jupiter WASP-12b
• Exploiting the transit timing capabilities of Ariel
• The GAPS Programme at TNG. LXV. Precise density measurement of TOI-1430 b, a young planet with an evaporating atmosphere