WASP-4 transit timing variation from a comprehensive set of 129 transits

Abstract

We homogeneously reanalyse $124$ transit light curves for the WASP-4 b hot Jupiter. This set involved new observations secured in 2019 and nearly all observations mentioned in the literature, including high-accuracy GEMINI/GMOS transmission spectroscopy of 2011-2014 and TESS observations of 2018. The analysis confirmed a nonlinear TTV trend with $P/|\dot{P}|\sim (17-30)$ Myr (1-sigma range), implying only half of the initial decay rate estimation. The trend significance is at least $3.4$-sigma in the agressively conservative treatment. Possible radial acceleration due to unseen companions is not revealed in Doppler data covering seven years 2007-2014, and radial acceleration of $-15$ m s${}^{-1}$yr${}^{-1}$ reported in a recent preprint by another team is not confirmed. If present, it is a very nonlinear RV variation. Assuming that the entire TTV is tidal in nature, the tidal quality factor $Q_{\star }^{\prime }\sim (4.5-8.5)\cdot 10^4$ does not reveal a convincing disagreement with available theory predictions.

Accepted to MNRAS Letters. 5 pages, 1 figure. TTV data files and an online-only PDF supplement are in the download archive

References in corpus (8)

• Improved parameters for the transiting hot Jupiters WASP-4b and WASP-5b
• WASP-4b: a 12th-magnitude transiting hot-Jupiter in the Southern hemisphere
• Accounting for velocity jitter in planet search surveys
• Benchmarking the power of amateur observatories for TTV exoplanets detection
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• Enhanced models for stellar Doppler noise reveal hints of a 13-year activity cycle of 55 Cancri
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Cited by in corpus (9)

• ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations
• Discovery and characterization of the exoplanets WASP-148b and c. A transiting system with two interacting giant planets
• Examining the orbital decay targets KELT-9 b, KELT-16 b and WASP-4 b, and the transit-timing variations of HD 97658 b
• Evidence of Long-Term Period Variations in the Exoplanet Transit Database (ETD)
• TESS Observations of the Hot Jupiter Exoplanet XO-6b: No Evidence of Transit Timing Variations
• The apparent tidal decay of WASP-4 b can be explained by the Rømer effect
• A search for transit timing variations in the HATS-18 planetary system
• The impact of photospheric brightness field on exoplanetary transit timings and the TTV excess of HD 189733 b
• Characterizing the WASP-4 system with TESS and radial velocity data: Constraints on the cause of the hot Jupiter's changing orbit and evidence of an outer planet