arXiv subjects

T. Guillot

Publications and source records attributed to T. Guillot.

At least 19 recordsLinked to original sources

arXiv2026

The Hill sphere transits of Beta Pictoris c and the search for another 1981-like event

Beta Pictoris is a young and nearby planetary system hosting an edge-on debris disk and at least three gas-giant planets. Their circumplanetary environments could host exomoons and rings, a detection of which would be highly informative for moon and planet formation theories. A photometric fluctuation of about 4% was seen towards Beta Pictoris in 1981, indicating the transit of dust in the system, which could be associated with the Hill spheres of the two inner planets. We search for the origin of the 1981 event by searching for an analogous event in multi-epoch photometry from 2017 to 2023, and look for signs of circumplanetary material in transits of the Hill sphere of Beta Pictoris c. Observations from the BRITE satellite, and the bRing and ASTEP observatories are fitted to a model of the 1981 event to search for a similar event, and also search for a signal consistent with a circumplanetary disk transit using a simple flat disk model. No compelling evidence for a 1981 event during a Hill sphere primary transit is found, although we do find a candidate event around 2019 July 26. Due to the uncertainty in the time of closest projected separation of Beta Pictoris c, a search for a disk during the primary transit of 2018 could not be robustly determined, but bRing photometry for the second primary transit places an upper limit on the dust content of the Hill sphere of ~ $10^{22}$ grams of material. With no compelling detection of an event similar to that seen in 1981 during the transits of Beta Pictoris c in the photometric time series, we rule out the hypothesis that this event was related to the Hill spheres of Beta Pictoris c and Beta Pictoris b. Future observations of the next Hill sphere transit in 2028 can be realised with both ground-based observatories and with PLATO, whose first long duration science pointing will include Beta Pictoris.

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arXiv2026

HD 148797: A bright F-type star with two moderate-period low-density sub-Jovian planets. Compact multi-planet architectures are common in the Neptunian savanna

We report the confirmation and characterisation of two moderate-period sub-Jovian planets transiting the bright F-type star HD 148797 (G=9.4 mag, Teff=6441 +/- 51 K). Using photometric time series from TESS and CHEOPS, we determine orbital periods of 42.1 d for HD 148797 b and 68.2 d for HD 148797 c, putting the period ratio very close to the golden mean at 1.619 and therefore near several strong harmonics, and measure planetary radii of 8.25 +/- 0.37 RE and 8.37 +/- 0.38 RE, respectively. We detect significant anti-correlated transit-timing variations for both planets, which contain enough harmonic information to yield photodynamical masses of 39.3 +13 -8.5 ME for HD 148797 b and 39.6 +/- 9.3 ME for HD 148797 c. The corresponding bulk densities, 0.39 +/- 0.12 and 0.377 +/- 0.084 g/cm3, place both planets among the low-density sub-Jovians of the Neptunian savanna. The architecture of HD 148797 is not unusual within this regime: we find that detected multi-system fractions in the savanna remain at ~70-90%, and that most savanna multi-planet systems contain at least one adjacent planet pair with Pout/Pin < 3. This pattern suggests that savanna sub-Jovians are commonly found in dynamically cold systems, consistent with smoother migration pathways such as disk-driven migration rather than disruptive high-eccentricity tidal migration. As a bright, co-evolved system hosting two warm savanna sub-Jovians with similar radii and masses, HD 148797 is also a promising target for comparative atmospheric characterisation.

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arXiv2026

A decade of monitoring the HIP 41378's planetary system

Multi-planetary systems provide key constraints on planet formation and evolution, as their architecture encodes the dynamical history of planets formed within a common protoplanetary disk. However, the current population remains strongly biased toward compact, short-period systems, and only a limited number of such systems with measured masses and radii are known. HIP 41378 is an exceptional system hosting five transiting planets with orbital periods up to 1.5 years, including an ultra-low density planet HIP 41378 f. The outer transiting planets d and e remained poorly constrained with unknown periods and masses, leaving the system architecture only partially characterised. We present long-term monitoring of this target with high-precision radial-velocity (RV) instruments (HARPS, HARPS-N, HIRES, and ESPRESSO) and space-based photometry spanning 2015-2024. We detect RV signals for all the planets, confirming their orbital periods and constraining their masses. In particular, the RV data strongly favour an orbital period of Pd = 278 days for planet d and refine the orbital period of planet e to Pe = 393+3-5 days. We measure a new mass of Mf = 25 \pm 5 earth masses for HIP 41378 f, confirming its super-puff nature with a bulk density of 0.166+0.033-0.036 g cm3. We also confirm the planetary nature of HIP 41378 g, a non-transiting planet with a 63-day period, and determine its minimum mass. In addition, the RVs reveal a long-period signal, with P = 2602+468-433 days, which we attribute to the candidate planet HIP 41378 h, although a stellar magnetic cycle cannot be excluded. Finally, we investigate the system's dynamical architecture and resonant structure, assess its completeness by constraining additional undetected planets, and discuss the implications for the origin and internal structure of the remarkable planet HIP 41378 f.

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arXiv2026

Photodynamical modeling of TOI-4504 reveals its deeply resonant state and similarity to GJ 876

The K-dwarf TOI-4504 hosts two giant planets in 2:1 mean-motion resonance, with orbital periods of 41.3 days (planet d) and 82.8 days (planet c). They exhibit among the largest known absolute transit-timing variations, with respective peak-to-node amplitudes up to 5 and 3 days. Newer TESS data show that the previously non-transiting planet d has now precessed into transiting, and we derive updated system parameters with significant discrepancies with the discovery paper. The revised parameters place planets d and c deep in the resonance and close to or in the fully-relaxed limit-cycle state, with the resonant and secular modes interfering nonlinearly to induce non-zero relaxed free eccentricities which precess at the same rate as the forced eccentricities and the longitude of conjunctions, in turn enabling precise measurement of the full eccentricities and apsidal angles. We discuss the predictions of linear theory and how it can be used to understand the true state of the system revealed by N-body integrations, and more generally why it is that the posteriors of systems more compact than 2:1 tend to suffer from significant eccentricity degeneracy. We show that the extraordinary dynamical states of the giant pairs orbiting TOI-4504 and the M-dwarf GJ 876 are remarkably similar, in spite of the significant difference in their host-star masses, and discuss the implications for damping timescales during the relatively gentle formation process of Type II migration.

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arXiv2026

A data-driven estimate of the protosolar helium mass fraction

The protosolar helium mass-fraction is a key ingredient of solar, planetary models and enrichment laws. However, the assumed values often rely on simplified descriptions of the transport of chemicals in solar models. They are also based on the inferred helium mass fraction in the solar convective envelope, which is itself sensitive to uncertainties in the solar equation of state. We update the reference protosolar helium abundance by including the effects of macroscopic mixing at the base of the convective zone and more recent determinations of the helium mass fraction in the convective envelope. We combine results from our inversions to spectroscopic abundances, as well as literature values to provide a robust interval of the current helium mass fraction in the convective zone. We combine this measurement to models including light element depletion to provide an udpated protosolar helium abundance. We show that macroscopic mixing at the base of the envelope is key to infer protosolar helium. We find a revised interval of primordial helium mass fraction of 0.27575 +- 0.00315 slightly lower than previous estimates when combining our latest estimate of surface helium mass fraction and spectroscopic abundances. We find that the effects of macroscopic mixing are partially compensated by an increase in the inferred solar helium mass fraction in recent studies. We also derive more precise estimates based on various reference works in the litterature. Using the usual surface helium mass fraction, the primordial helium mass fraction drops to 0.2669 +- 0.00415 due to the inclusion of macroscopic mixing. The dominant source of uncertainty is found the surface helium abundance inferred from helioseismic constraints and more specifically, the impact on the equation of state of the solar material on this inference result.

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arXiv2025

Structure of Jupiter's High-Latitude Storms: Folded Filamentary Regions Revealed by Juno

Sprawling, turbulent cloud formations dominate the meteorology of Jupiter's mid-to-high latitudes, known as Folded Filamentary Regions (FFRs). A multi-wavelength characterisation by Juno reveals the spatial distribution, vertical structure, and energetics of the FFRs. The cloud tops display multiple lobes of stratiform aerosols, separated by darker, cloud-free lanes, and embedded with smaller eddies and high-altitude cumulus clouds. These cyclonic FFRs are microwave-bright in shallow-sounding wavelengths ($p<5$ bars) and microwave-dark in deep-sounding wavelengths ($p>10$ bars), with the transition potentially associated with the water condensation layer (6-7 bars). Associating microwave contrasts with temperature anomalies, this implies despinning of cyclonic eddies above/below their mid-planes. Despite deep roots (being detectable in wavelengths sounding $\sim100$ bars), they are ``pancake vortices'' with horizontal extents at least an order of magnitude larger than their depth. In the northern hemisphere, FFRs are most common in cyclonic belts poleward of $40^\circ$N (all latitudes are planetocentric), particularly a North Polar Filamentary Belt (NPFB) near $66-70^\circ$N that defines the transition from organised belts/zones to the chaotic polar domain. This distribution explains the high lightning rates from $45-80^\circ$N, peaking in a belt poleward of $52.3^\circ$N, which may trace the availability of water for moist convection. Many observed lightning flashes can be associated to specific FFRs containing bright storms, but some FFRs display no activity, suggesting quiescent periods during storm evolution. Analogies to Earth's oceanic eddies suggest that cyclones deform isentropic surfaces at their midplanes, raising deep water-rich layers upwards to promote moist convection, release latent heat, and inject clouds into the upper troposphere.

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arXiv2025

TOI-7510: A solar-analog system of three transiting giant planets near a Laplace resonance chain

We report the confirmation and initial characterization of a compact and dynamically rich multiple giant planet system orbiting the solar analog TOI-7510. The system was recently identified as a candidate two-planet system in a machine-learning search of the TESS light curves. Using TESS data and photometric follow-up observations with ASTEP, CHEOPS, and EulerCam, we show that one transit was initially misattributed and that the system consists of three transiting giant planets with orbital periods of 11.5, 22.6, and 48.9 days. The planets have radii of 0.65, 0.96, and 0.94 R_J, making them the largest known trio of transiting planets. The system architecture lies near a 4:2:1 mean motion resonant chain, inducing large transit timing variations for all three planets. Photodynamical modeling gives mass estimates of 0.057, 0.41, and 0.60 M_J and favors low eccentricities and mutual inclinations. TOI-7510 is an interesting system for investigating the dynamical interactions and formation histories of compact systems of giant planets.

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arXiv2024

Characterisation of the Warm-Jupiter TOI-1130 system with CHEOPS and photo-dynamical approach

Among the thousands of exoplanets discovered to date, approximately a few hundred gas giants on short-period orbits are classified as "lonely" and only a few are in a multi-planet system with a smaller companion on a close orbit. The processes that formed multi-planet systems hosting gas giants on close orbits are poorly understood, and only a few examples of this kind of system have been observed and well characterised. Within the contest of multi-planet system hosting gas-giant on short orbits, we characterise TOI-1130 system by measuring masses and orbital parameters. This is a 2-transiting planet system with a Jupiter-like planet (c) on a 8.35 days orbit and a Neptune-like planet (b) on an inner (4.07 days) orbit. Both planets show strong anti-correlated transit timing variations (TTVs). Furthermore, radial velocity (RV) analysis showed an additional linear trend, a possible hint of a non-transiting candidate planet on a far outer orbit. Since 2019, extensive transit and radial velocity observations of the TOI-1130 have been acquired using TESS and various ground-based facilities. We present a new photo-dynamical analysis of all available transit and RV data, with the addition of new CHEOPS and ASTEP+ data that achieve the best precision to date on the planetary radii and masses and on the timings of each transit. We were able to model interior structure of planet b constraining the presence of a gaseous envelope of H/He, while it was not possible to assess the possible water content. Furthermore, we analysed the resonant state of the two transiting planets, and we found that they lie just outside the resonant region. This could be the result of the tidal evolution that the system underwent. We obtained both masses of the planets with a precision less than 1.5%, and radii with a precision of about 1% and 3% for planet b and c, respectively.

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arXiv2024

Evidence for transit-timing variations of the 11 Myr exoplanet TOI-1227 b

TOI-1227 b is an 11 Myr old validated transiting planet in the middle of its contraction phase, with a current radius of 0.85 R$_J$. It orbits a low-mass pre-main sequence star (0.170 M$_\odot$, 0.56 R$_\odot$) every 27.4 days. The magnetic activity of its young host star induces radial velocity jitter and prevents good measurements of the planetary mass. We gathered additional transit observations of TOI-1227 b with space- and ground-based telescopes, and we detected highly significant transit-timing variations (TTVs). Their amplitude is about 40 minutes and their dominant timescale is longer than 3.7 years. Their most probable origin is dynamical interactions with additional planets in the system. We modeled the TTVs with inner and outer perturbers near first and second order resonances; several orbital configurations provide an acceptable fit. More data are needed to determine the actual orbital configuration and eventually measure the planetary masses. These TTVs and an updated transit chromaticity analysis reinforce the evidence that TOI-1227 b is a planet.

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arXiv2023

TOI-1130: A photodynamical analysis of a hot Jupiter in resonance with an inner low-mass planet

The TOI-1130 is a known planetary system around a K-dwarf consisting of a gas giant planet, TOI-1130 c, on an 8.4-day orbit, accompanied by an inner Neptune-sized planet, TOI-1130 b, with an orbital period of 4.1 days. We collected precise radial velocity (RV) measurements of TOI-1130 with the HARPS and PFS spectrographs as part of our ongoing RV follow-up program. We perform a photodynamical modeling of the HARPS and PFS RVs, and transit photometry from the Transiting Exoplanet Survey Satellite (TESS) and the TESS Follow-up Observing Program. We determine the planet masses and radii of TOI-1130 b and TOI-1130 c to be Mb = 19.28 $\pm$ 0.97 M$_\oplus$ and Rb = 3.56 $\pm$ 0.13 R$_\oplus$, and Mc = 325.59 $\pm$ 5.59 M$_\oplus$ and Rc = 13.32+1.55-1.41 R$_\oplus$, respectively. We spectroscopically confirm TOI-1130 b that was previously only validated. We find that the two planets orbit with small eccentricities in a 2:1 resonant configuration. This is the first known system with a hot Jupiter and an inner lower mass planet locked in a mean-motion resonance. TOI-1130 belongs to the small yet increasing population of hot Jupiters with an inner low-mass planet that challenges the pathway for hot Jupiter formation. We also detect a linear RV trend possibly due to the presence of an outer massive companion.

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arXiv2023

Rainy downdrafts in abyssal atmospheres

Results from Juno's microwave radiometer indicate non-uniform mixing of ammonia vapor in Jupiter's atmosphere down to tens of bars, far beneath the cloud level. Helioseismic observations suggest solar convection may require narrow, concentrated downdrafts called entropy rain to accommodate the Sun's luminosity. Both observations suggest some mechanism of non-local convective transport. We seek to predict the depth that a concentrated density anomaly can reach before efficiently mixing with its environment in bottomless atmospheres. We modify classic self-similar analytical models of entraining thermals to account for the compressibility of an abyssal atmosphere. We compare these models to the output of high resolution three dimensional fluid dynamical simulations to more accurately model the chaotic influence of turbulence. We find that localized density anomalies propagate down to ~3-8 times their initial size without substantially mixing with their environment. Our analytic model accurately predicts the initial flow, but the self-similarity assumption breaks down after the flow becomes unstable at a characteristic penetration depth. In the context of Jupiter, our findings suggest that precipitation concentrated into localized downdrafts of size ~20km can coherently penetrate to on the order of a hundred kilometers (tens of bars) beneath its initial vaporization level without mixing with its environment. This finding is consistent with expected convective storm length-scales, and Juno MWR measurements of ammonia depletion. Compositional gradients of volatiles beneath their cloud levels may be common on stormy giant planets. In the context of the Sun, we find that turbulent downdrafts in abyssal atmospheres cannot maintain their coherence through the Sun's convective layer, a potential challenge for the entropy rain hypothesis.

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arXiv2023

Jupiter's interior from Juno: Equation-of-state uncertainties and dilute core extent

The Juno mission has provided measurements of Jupiter s gravity field with an outstanding level of accuracy, leading to better constraints on the interior of the planet. Improving our knowledge of the internal structure of Jupiter is key to understanding its formation and evolution but is also important in the framework of exoplanet exploration. In this study, we investigated the differences between the state-of-the-art equations of state and their impact on the properties of interior models. Accounting for uncertainty on the hydrogen and helium equation of state, we assessed the span of the interior features of Jupiter. We carried out an extensive exploration of the parameter space and studied a wide range of interior models using Markov chain Monte Carlo (MCMC) simulations. To consider the uncertainty on the equation of state, we allowed for modifications of the equation of state in our calculations. Our models harbour a dilute core and indicate that Jupiter s internal entropy is higher than what is usually assumed from the Galileo probe measurements. We obtain solutions with extended dilute cores, but contrary to other recent interior models of Jupiter, we also obtain models with small dilute cores. The dilute cores in such solutions extend to 20% of Jupiter s mass, leading to better agreement with formation evolution models. We conclude that the equations of state used in Jupiter models have a crucial effect on the inferred structure and composition. Further explorations of the behaviour of hydrogen helium mixtures at the pressure and temperature conditions in Jupiter will help to constrain the interior of the planet, and therefore its origin.

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arXiv2022

ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations

The ExoClock project has been created with the aim of increasing the efficiency of the Ariel mission. It will achieve this by continuously monitoring and updating the ephemerides of Ariel candidates over an extended period, in order to produce a consistent catalogue of reliable and precise ephemerides. This work presents a homogenous catalogue of updated ephemerides for 450 planets, generated by the integration of $\sim$18000 data points from multiple sources. These sources include observations from ground-based telescopes (ExoClock network and ETD), mid-time values from the literature and light-curves from space telescopes (Kepler/K2 and TESS). With all the above, we manage to collect observations for half of the post-discovery years (median), with data that have a median uncertainty less than one minute. In comparison with literature, the ephemerides generated by the project are more precise and less biased. More than 40\% of the initial literature ephemerides had to be updated to reach the goals of the project, as they were either of low precision or drifting. Moreover, the integrated approach of the project enables both the monitoring of the majority of the Ariel candidates (95\%), and also the identification of missing data. The dedicated ExoClock network effectively supports this task by contributing additional observations when a gap in the data is identified. These results highlight the need for continuous monitoring to increase the observing coverage of the candidate planets. Finally, the extended observing coverage of planets allows us to detect trends (TTVs - Transit Timing Variations) for a sample of 19 planets. All products, data, and codes used in this work are open and accessible to the wider scientific community.

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arXiv2022

Jupiter's inhomogeneous envelope

While Jupiter's massive gas envelope consists mainly of hydrogen and helium, the key to understanding Jupiter's formation and evolution lies in the distribution of the remaining (heavy) elements. Before the Juno mission, the lack of high-precision gravity harmonics precluded the use of statistical analyses in a robust determination of the heavy-elements distribution in Jupiter's envelope. In this paper, we assemble the most comprehensive and diverse collection of Jupiter interior models to date and use it to study the distribution of heavy elements in the planet's envelope. We apply a Bayesian statistical approach to our interior model calculations, reproducing the Juno gravitational and atmospheric measurements and constraints from the deep zonal flows. Our results show that the gravity constraints lead to a deep entropy of Jupiter corresponding to a 1 bar temperature 5-15 K higher than traditionally assumed. We also find that uncertainties in the equation of state are crucial when determining the amount of heavy elements in Jupiter's interior. Our models put an upper limit to the inner compact core of Jupiter of 7 Earth masses, independently on the structure model (with or without dilute core) and the equation of state considered. Furthermore, we robustly demonstrate that Jupiter's envelope is inhomogenous, with a heavy-element enrichment in the interior relative to the outer envelope. This implies that heavy element enrichment continued through the gas accretion phase, with important implications for the formation of giant planets in our solar system and beyond.

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arXiv2021

Convective storms and atmospheric vertical structure in Uranus and Neptune

The Ice Giants Uranus and Neptune have hydrogen-based atmospheres with several constituents that condense in their cold upper atmospheres. A small number of bright cloud systems observed in both planets are good candidates for moist convective storms, but their observed properties (size, temporal scales and cycles of activity) differ from moist convective storms in the Gas Giants. These clouds and storms are possibly due to methane condensation and observations also suggest deeper clouds of hydrogen sulfide (H$_2$S) at depths of a few bars. Even deeper, thermochemical models predict clouds of ammonia hydrosulfide (NH$_4$SH) and water at pressures of tens to hundreds of bars, forming extended deep weather layers. Because of hydrogen's small molecular weight and the high abundance of volatiles, their condensation imposes a strongly stabilizing vertical gradient of molecular weight larger than the equivalent one in Jupiter and Saturn. The resulting inhibition of vertical motions should lead to a moist convective regime that differs significantly from the one occurring on nitrogen-based atmospheres like those of Earth or Titan. As a consequence, the thermal structure of the deep atmospheres of Uranus and Neptune is not well understood. Similar processes might occur at the deep water cloud of Jupiter in Saturn, but the Ice Giants offer the possibility to study these physical aspects in the upper methane cloud layer. A combination of orbital and in situ data will be required to understand convection and its role in atmospheric dynamics in the Ice Giants, and by extension, in hydrogen atmospheres including Jupiter, Saturn and giant exoplanets.

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arXiv2021

Jupiter's Temperate Belt/Zone Contrasts Revealed at Depth by Juno Microwave Observations

Juno Microwave Radiometer (MWR) observations of Jupiter's mid-latitudes reveal a strong correlation between brightness temperature contrasts and zonal winds, confirming that the banded structure extends throughout the troposphere. However, the microwave brightness gradient is observed to change sign with depth: the belts are microwave-bright in the $p<5$ bar range and microwave-dark in the $p>10$ bar range. The transition level (which we call the jovicline) is evident in the MWR 11.5 cm channel, which samples the 5-14 bar range when using the limb-darkening at all emission angles. The transition is located between 4 and 10 bars, and implies that belts change with depth from being NH$_3$-depleted to NH$_3$-enriched, or from physically-warm to physically-cool, or more likely a combination of both. The change in character occurs near the statically stable layer associated with water condensation. The implications of the transition are discussed in terms of ammonia redistribution via meridional circulation cells with opposing flows above and below the water condensation layer, and in terms of the `mushball' precipitation model, which predicts steeper vertical ammonia gradients in the belts versus the zones. We show via the moist thermal wind equation that both the temperature and ammonia interpretations can lead to vertical shear on the zonal winds, but the shear is $\sim50\times$ weaker if only NH$_3$ gradients are considered. Conversely, if MWR observations are associated with kinetic temperature gradients then it would produce zonal winds that increase in strength down to the jovicline, consistent with Galileo probe measurements; then decay slowly at higher pressures.

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arXiv2021

Constraints on the latitudinal profile of Jupiter's deep jets

The observed zonal winds at Jupiter's cloud tops have been shown to be closely linked to the asymmetric part of the planet's measured gravity field. However, other measurements suggest that in some latitudinal regions the flow below the clouds might be somewhat different from the observed cloud-level winds. Here we show, using both the symmetric and asymmetric parts of the measured gravity field, that the observed cloud-level wind profile between 25$^{\circ}$S and 25$^{\circ}$N must extend unaltered to depths of thousands of kilometers. Poleward, the midlatitude deep jets also contribute to the gravity signal, but might differ somewhat from the cloud-level winds. We analyze the likelihood of this difference and give bounds to its strength. We also find that to match the gravity measurements, the winds must project inward in the direction parallel to Jupiter's spin axis, and that their decay inward should be in the radial direction.

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arXiv2021

The $β$ Pictoris b Hill sphere transit campaign. Paper I: Photometric limits to dust and rings

Photometric monitoring of Beta Pictoris in 1981 showed anomalous fluctuations of up to 4% over several days, consistent with foreground material transiting the stellar disk. The subsequent discovery of the gas giant planet Beta Pictoris b and the predicted transit of its Hill sphere to within 0.1 au projected distance of the planet provided an opportunity to search for the transit of a circumplanetary disk in this $21\pm 4$ Myr-old planetary system. Continuous broadband photometric monitoring of Beta Pictoris requires ground-based observatories at multiple longitudes to provide redundancy and to provide triggers for rapid spectroscopic followup. These observatories include the dedicated Beta Pictoris monitoring observatory bRing at Sutherland and Siding Springs, the ASTEP400 telescope at Concordia, and observations from the space observatories BRITE and Hubble Space Telescope. We search the combined light curves for evidence of short period transient events caused by rings and for longer term photometric variability due to diffuse circumplanetary material. We find no photometric event that matches with the event seen in November 1981, and there is no systematic photometric dimming of the star as a function of the Hill sphere radius. We conclude that the 1981 event was not caused by the transit of a circumplanetary disk around Beta Pictoris b. The upper limit on the long term variability of Beta Pictoris places an upper limit of $1.8\times 10^{22}$ g of dust within the Hill sphere. Circumplanetary material is either condensed into a non-transiting disk, is condensed into a disk with moons that has a small obliquity, or is below our detection threshold. This is the first time that a dedicated international campaign has mapped the Hill sphere transit of a gas giant extrasolar planet at 10 au.

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