TESS Observations of the Hot Jupiter Exoplanet XO-6b: No Evidence of Transit Timing Variations

Abstract

From previous ground-based observations, the hot Jupiter exoplanet XO-6b was reported to exhibit apparently periodic transit timing variations (TTVs), with a semi-amplitude of 14 minutes and a period of about 450 days. These variations were interpreted as being due to a resonant perturbation between XO-6b and a hitherto unknown low-mass planet orbiting the same star. To understand this enigmatic planetary system better, we analysed three sectors of data, spanning over seven months, from the Transiting Exoplanet Survey Satellite (TESS), which produces high-quality light curves that are well suited to characterizing exoplanets and searching for TTVs. Here we present an updated orbital period of 3.7649893 $\pm$ 0.0000037 days and a transit epoch of 2456652.7157 $\pm$ 0.0022 BJD${}_{TDB}$. The planetary parameters we report, while consistent with their discovery values, have greatly improved precision. Notably, we find no evidence for TTVs: we can rule out TTVs $\gtrsim$ 2.5 minutes at the 3$\sigma$ level. Therefore, the TESS data have sufficient precision and time baseline to reveal readily the previously reported TTVs of approximately 10 minutes. Our findings highlight TESS's capabilities for robust follow-up, and confirm that TTVs are rarely seen in hot Jupiters, unlike is the case with small planets.

Accepted for publication in AJ. 16 pages, 8 figures

References in corpus (24)

• Achieving better than 1 minute accuracy in the Heliocentric and Barycentric Julian Dates
• EXOFAST: A fast exoplanetary fitting suite in IDL
• The effect of red noise on planetary transit detection
• Homogeneous studies of transiting extrasolar planets. I. Light curve analyses
• Kepler constraints on planets near hot Jupiters
• EVEREST: Pixel Level Decorrelation of K2 Light curves
• The Orbit of WASP-12b is Decaying
• A method for the direct determination of the surface gravities of transiting extrasolar planets
• Connecting planet formation and astrochemistry: A main sequence for C/O in hot-exoplanetary atmospheres
• WASP-4b Arrived Early for the TESS Mission
• Spin-orbit Misalignment as a Driver of the Kepler Dichotomy
• Spin-Orbit Angles of Kepler-13Ab and HAT-P-7b from Gravity-Darkened Transit Light Curves
• Utilizing Small Telescopes Operated by Citizen Scientists for Transiting Exoplanet Follow-up
• Investigating the physical properties of transiting hot Jupiters with the 1.5-m Kuiper Telescope
• WASP-4 is Accelerating Toward the Earth
• Discovery of XO-6b: a hot Jupiter transiting a fast rotating F5 star on an oblique orbit
• Homogeneously derived transit timings for 17 exoplanets and reassessed TTV trends for WASP-12 and WASP-4
• TOI-216b and TOI-216c: Two warm, large exoplanets in or slightly wide of the 2:1 orbital resonance
• Spin-Orbit Misalignment and Precession in the Kepler-13Ab Planetary System
• WASP-4 transit timing variation from a comprehensive set of 129 transits
• The clockwork is moving on -- a combined analysis of TESS and Kepler measurements of Kepler-13Ab
• TESS Data for Asteroseismology: Timing verification
• Robustly detecting changes in warm Jupiters' transit impact parameters
• Periodic transit timing variations and refined system parameters of the exoplanet XO-6b

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• TESS Transit Timing of Hundreds of Hot Jupiters
• Empirical limb-darkening coefficients & transit parameters of known exoplanets from TESS
• Decaying Orbit of the Hot Jupiter WASP-12b: Confirmation with TESS Observations
• ExoClock project II: A large-scale integrated study with 180 updated exoplanet ephemerides
• BOWIE-ALIGN: A JWST comparative survey of aligned vs misaligned hot Jupiters to test the dependence of atmospheric composition on migration history
• Looking For Timing Variations in the Transits of 16 Exoplanets
• Rapidly rotating stars and their transiting planets: KELT-17b, KELT-19Ab, and KELT-21b in the CHEOPS and TESS era
• 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