arXiv subjects

Gael Chauvin

Publications and source records attributed to Gael Chauvin.

At least 37 records · Page 2Linked to original sources

arXiv2023

Emission line variability of young 10-30 Mjup companions : I. The case of GQ Lup b and GSC 06214-00210 b

Emission lines indicative of active accretion have been seen on a handful of low-mass companions (M < 30 MJup) to stars. Line variability is ubiquitous on stellar accretors but has never been characterized in detail on low-mass companions and can give insights on the accretion mechanism at play. We investigate the emission line variability of two low-mass companions (M<30 MJup) to stars to understand their accretion mechanisms. Using J-band observations, we analyze the short to long-term variability of the HI Paschen β emission line (1.282 μm) for GQ Lup b and GSC 06214-00210 b. Archival spectroscopic observations are also examined to extend the time span. We compare their line profiles and intensities to more massive accretors and magnetospheric accretion and shock models. Both objects have HI Paschen β flux variability that is moderate at short timescales (< 50 %) and increases at longer timescales (~1000 % on decade timescales), resembling classical T Tauri stars. GQ Lup b's line profiles are compatible with magnetospheric accretion. GSC 06214-00210 b's profiles are reproduced by both magnetospheric accretion and shock models, except for the brightest epoch for which the shock model is highly favored. Both companions have C/O values broadly consistent with solar values. While magnetospheric accretion is favored for GQ Lup b, higher resolution (R > 10000) observations are required to disentangle the two (non-exclusive) line formation mechanisms. The similarity in variability behavior may support similar accretion mechanisms between these low-mass companions and classical T Tauri stars. The significant variability observed at months and longer timescales could explain the low yield of Hα imaging campaigns.

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arXiv2023

The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems I: High Contrast Imaging of the Exoplanet HIP 65426 b from 2-16 $μ$m

We present JWST Early Release Science (ERS) coronagraphic observations of the super-Jupiter exoplanet, HIP 65426 b, with the Near-Infrared Camera (NIRCam) from 2-5 $μ$m, and with the Mid-Infrared Instrument (MIRI) from 11-16 $μ$m. At a separation of $\sim$0.82" (86$^{+116}_{-31}$ au), HIP 65426 b is clearly detected in all seven of our observational filters, representing the first images of an exoplanet to be obtained by JWST, and the first ever direct detection of an exoplanet beyond 5 $μ$m. These observations demonstrate that JWST is exceeding its nominal predicted performance by up to a factor of 10, depending on separation and subtraction method, with measured 5$σ$ contrast limits of $\sim$1$\times10^{-5}$ and $\sim$2$\times10^{-4}$ at 1" for NIRCam at 4.4 $μ$m and MIRI at 11.3 $μ$m, respectively. These contrast limits provide sensitivity to sub-Jupiter companions with masses as low as 0.3$M_\mathrm{Jup}$ beyond separations of $\sim$100 au. Together with existing ground-based near-infrared data, the JWST photometry are well fit by a BT-SETTL atmospheric model from 1-16 $μ$m, and span $\sim$97% of HIP 65426 b's luminous range. Independent of the choice of model atmosphere we measure an empirical bolometric luminosity that is tightly constrained between $\mathrm{log}\!\left(L_\mathrm{bol}/L_{\odot}\right)$=-4.31 to $-$4.14, which in turn provides a robust mass constraint of 7.1$\pm$1.2 $M_\mathrm{Jup}$. In totality, these observations confirm that JWST presents a powerful and exciting opportunity to characterise the population of exoplanets amenable to high-contrast imaging in greater detail.

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arXiv2023

The beta Pictoris system: Setting constraints on the planet and the disk structures at mid-IR wavelengths with NEAR

[abridged] We analyzed mid-infrared high-contrast coronagraphic images of the beta Pictoris system, taking advantage of the NEAR experiment using the VLT/VISIR instrument. The goal of our analysis is to investigate both the detection of the planet beta Pictoris b and of the disk features at mid-IR wavelengths. In addition, by combining several epochs of observation, we expect to constrain the position of the known clumps and improve our knowledge on the dynamics of the disk. To evaluate the planet b flux contribution, we extracted the photometry and compared it to the flux published in the literature. In addition, we used previous data from T-ReCS and VISIR, to study the evolution of the position of the southwest clump that was initially observed in the planetary disk back in 2003. While we did not detect the planet b, we were able to put constraints on the presence of circumplanetary material, ruling out the equivalent of a Saturn-like planetary ring around the planet. The disk presents several noticeable structures, including the known southwest clump. Using a 16-year baseline, sampled with five epochs of observations, we were able to examine the evolution of the clump: the clump orbits in a Keplerian motion with an sma of 56.1+-0.4 au. In addition to the known clump, the images clearly show the presence of a second clump on the northeast side of the disk and fainter and closer structures that are yet to be confirmed. We found correlations between the CO clumps detected with ALMA and the mid-IR images. If the circumplanetary material were located at the Roche radius, the maximum amount of dust determined from the flux upper limit around beta Pictoris b would correspond to the mass of an asteroid of 5 km in diameter. Finally, the Keplerian motion of the southwestern clump is possibly indicative of a yet-to-be-detected planet or signals the presence of a vortex.

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arXiv2022

The JWST Early Release Science Program for the Direct Imaging & Spectroscopy of Exoplanetary Systems

The direct characterization of exoplanetary systems with high contrast imaging is among the highest priorities for the broader exoplanet community. As large space missions will be necessary for detecting and characterizing exo-Earth twins, developing the techniques and technology for direct imaging of exoplanets is a driving focus for the community. For the first time, JWST will directly observe extrasolar planets at mid-infrared wavelengths beyond 5$μ$m, deliver detailed spectroscopy revealing much more precise chemical abundances and atmospheric conditions, and provide sensitivity to analogs of our solar system ice-giant planets at wide orbital separations, an entirely new class of exoplanet. However, in order to maximise the scientific output over the lifetime of the mission, an exquisite understanding of the instrumental performance of JWST is needed as early in the mission as possible. In this paper, we describe our 55-hour Early Release Science Program that will utilize all four JWST instruments to extend the characterisation of planetary mass companions to $\sim$15$μ$m as well as image a circumstellar disk in the mid-infrared with unprecedented sensitivity. Our program will also assess the performance of the observatory in the key modes expected to be commonly used for exoplanet direct imaging and spectroscopy, optimize data calibration and processing, and generate representative datasets that will enable a broad user base to effectively plan for general observing programs in future cycles.

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arXiv2022

Increasing the raw contrast of VLT/SPHERE with the dark-hole technique. II. On-sky wavefront correction and coherent differential imaging

Context. Direct imaging of exoplanets takes advantage of state-of-the-art adaptive optics (AO) systems, coronagraphy, and post-processing techniques. Coronagraphs attenuate starlight to mitigate the unfavorable flux ratio between an exoplanet and its host star. AO systems provide diffraction-limited images of point sources and minimize optical aberrations that would cause starlight to leak through coronagraphs. Post-processing techniques then estimate and remove residual stellar speckles such as noncommon path aberrations (NCPAs) and diffraction from telescope obscurations. Aims. We aim to demonstrate an efficient method to minimize the speckle intensity due to NCPAs during an observing night on VLT/SPHERE. Methods. We implement an iterative dark-hole (DH) algorithm to remove stellar speckles on-sky before a science observation. It uses a pair-wise probing estimator and a controller based on electric field conjugation. This work presents the first such on-sky minimization of speckles with a DH technique on SPHERE. Results. We show the standard deviation of the normalized intensity in the raw images is reduced by a factor of up to 5 in the corrected region with respect to the current calibration strategy under median conditions for VLT. This level of contrast performance obtained with only 1 min of exposure time reaches median performances on SPHERE that use post-processing methods requiring 1h-long sequences of observations. We also present an alternative calibration method that takes advantage of the starlight coherence and improves the post-processed contrast levels rms by a factor of about 3. Conclusions. This on-sky demonstration represents a decisive milestone for the future design, development, and observing strategy of the next generation of ground-based exoplanet imagers for 10m to 40m telescope.

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arXiv2022

Efficiently combining Alpha CenA multi-epoch high-contrast imaging data. Application of K-Stacker to the 80 hrs NEAR campaign

Keplerian-Stacker is an algorithm able to combine multiple observations acquired at different epochs taking into account the orbital motion of a potential planet present in the images to boost the ultimate detection limit. In 2019, a total of 100 hours of observation were allocated to VLT VISIR-NEAR, a collaboration between ESO and Breakthrough Initiatives, to search for low mass planets in the habitable zone of the Alpha Cen AB binary system. A weak signal (S/N = 3) was reported around Alpha Cen A, at a separation of 1.1 a.u. which corresponds to the habitable zone. We have re-analysed the NEAR data using K-Stacker. This algorithm is a brute-force method able to find planets in time series of observations and to constrain their orbital parameters, even if they remain undetected in a single epoch. We scanned a total of about 3.5e+5 independent orbits, among which about 15 % correspond to fast moving orbits on which planets cannot be detected without taking into account the orbital motion. We find only a single planet candidate, which matches the C1 detection reported in Wagner et al. 2021. Despite the significant amount of time spent on this target, the orbit of this candidate remains poorly constrained due to these observations being closely distributed in 34 days. We argue that future single-target deep surveys would benefit from a K-Stacker based strategy, where the observations would be split over a significant part of the expected orbital period to better constrain the orbital parameters. This application of K-Stacker on high contrast imaging data in the mid-infrared demonstrates the capability of this algorithm to aid in the search for Earth-like planets in the habitable zone of the nearest stars with future instruments of the E-ELT such as METIS.

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arXiv2021

Dynamical masses for two M1 + mid-M dwarf binaries monitored during the SPHERE-SHINE survey

We present orbital fits and dynamical masses for HIP 113201AB and HIP 36985AB, two M1 + mid-M dwarf binary systems monitored as part of the SPHERE SHINE survey. To robustly determine ages via gyrochronology, we undertook a photometric monitoring campaign for HIP 113201 and for GJ 282AB, the two wide K star companions to HIP 36985, using the 40 cm Remote Observatory Atacama Desert (ROAD) telescope. We adopt ages of 1.2$\pm$0.1 Gyr for HIP 113201AB and 750$\pm$100 Myr for HIP 36985AB. To derive dynamical masses for all components of these systems, we used parallel-tempering Markov Chain Monte Carlo sampling to fit a combination of radial velocity, direct imaging, and Gaia and Hipparcos astrometry. Fitting the direct imaging and radial velocity data for HIP 113201 yields a primary mass of 0.54$\pm$0.03 M$_{\odot}$, fully consistent with its M1 spectral type, and a secondary mass of 0.145$\pm$ M$_{\odot}$. The secondary masses derived with and without including Hipparcos/Gaia data are more massive than the 0.1 M$_{\odot}$ estimated mass from the photometry of the companion. An undetected brown dwarf companion to HIP 113201B could be a natural explanation for this apparent discrepancy. At an age $>$1 Gyr, a 30 M$_{Jup}$ companion to HIP 113201B would make a negligible ($<$1$\%$) contribution to the system luminosity, but could have strong dynamical impacts. Fitting the direct imaging, radial velocity, and Hipparcos/Gaia proper motion anomaly for HIP 36985AB, we find a primary mass of 0.54$\pm$0.01 M$_{\odot}$ and a secondary mass of 0.185$\pm$0.001 M$_{\odot}$ which agree well with photometric estimates of component masses, the masses estimated from $M_{K}$-- mass relationships for M dwarf stars, and previous dynamical masses in the literature.

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arXiv2021

A wide-orbit giant planet in the high-mass b Centauri binary system

Planet formation occurs around a wide range of stellar masses and stellar system architectures. An improved understanding of the formation process can be achieved by studying it across the full parameter space, particularly toward the extremes. Earlier studies of planets in close-in orbits around high-mass stars have revealed an increase in giant planet frequency with increasing stellar mass until a turnover point at 1.9 solar masses, above which the frequency rapidly decreases. This could potentially imply that planet formation is impeded around more massive stars, and that giant planets around stars exceeding 3 solar masses may be rare or non-existent. However, the methods used to detect planets in small orbits are insensitive to planets in wide orbits. Here we demonstrate the existence of a planet at 560 times the Sun-Earth distance from the 6-10 solar mass binary b Centauri through direct imaging. The planet-to-star mass ratio of 0.10-0.17% is similar to the Jupiter-Sun ratio, but the separation of the detected planet is ~100 times wider than that of Jupiter. Our results show that planets can reside in much more massive stellar systems than what would be expected from extrapolation of previous results. The planet is unlikely to have formed in-situ through the conventional core accretion mechanism, but might have formed elsewhere and arrived to its present location through dynamical interactions, or might have formed via gravitational instability.

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arXiv2021

Revealing asymmetrical dust distribution in the inner regions of HD 141569

We obtained polarimetric differential imaging of a gas-rich debris disk around HD 141569A with SPHERE in the H-band to compare the scattering properties of the innermost ring at 44 au with former observations in total intensity with the same instrument. In polarimetric imaging, we observed that the intensity of the ring peaks in the south-east, mostly in the forward direction, whereas in total intensity imaging, the ring is detected only at the south. This noticeable characteristic suggests a non-uniform dust density in the ring. We implemented a density function varying azimuthally along the ring and generated synthetic images both in polarimetry and in total intensity, which are then compared to the actual data. We find that the dust density peaks in the south-west at an azimuthal angle of $220^{\circ} \sim 238^{\circ}$ with a rather broad width of $61^{\circ} \sim 127^{\circ}$. Although there are still uncertainties that remain in the determination of the anisotropic scattering factor, the implementation of an azimuthal density variation to fit the data proved to be robust. Upon elaborating on the origin of this dust density distribution, we conclude that it could be the result of a massive collision when we account for the effect of the high gas mass that is present in the system on the dynamics of grains. Using the outcome of this modelization, we further measured the polarized scattering phase function for the observed scattering angle between 33$^{\circ}$ and 147$^{\circ}$ as well as the spectral reflectance of the southern part of the ring between 0.98 $μ$m and 2.1 $μ$m. We tentatively derived the grain properties by comparing these quantities with MCFOST models and assuming Mie scattering. Our preliminary interpretation indicates a mixture of porous sub-micron sized astro-silicate and carbonaceous grains.

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arXiv2021

MAORY: A Multi-conjugate Adaptive Optics RelaY for ELT

MAORY is the adaptive optics module for ELT providing two gravity invariant ports with the same optical quality for two different client instruments. It enable high angular resolution observations in the near infrared over a large field of view (~1 arcmin2 ) by real time compensation of the wavefront distortions due to atmospheric turbulence. Wavefront sensing is performed by laser and natural guide stars while the wavefront sensor compensation is performed by an adaptive deformable mirror in MAORY which works together with the telescope's adaptive and tip tilt mirrors M4 and M5 respectively.

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arXiv2021

BEAST begins: Sample characteristics and survey performance of the B-star Exoplanet Abundance Study

While the occurrence rate of wide giant planets appears to increase with stellar mass at least up through the A-type regime, B-type stars have not been systematically studied in large-scale surveys so far. It therefore remains unclear up to what stellar mass this occurrence trend continues. The B-star Exoplanet Abundance Study (BEAST) is a direct imaging survey with the extreme adaptive optics instrument SPHERE, targeting 85 B-type stars in the young Scorpius-Centaurus (Sco-Cen) region with the aim to detect giant planets at wide separations and constrain their occurrence rate and physical properties. The statistical outcome of the survey will help determine if and where an upper stellar mass limit for planet formation occurs. In this work, we describe the selection and characterization of the BEAST target sample. Particular emphasis is placed on the age of each system, which is a central parameter in interpreting direct imaging observations. We implement a novel scheme for age dating based on kinematic sub-structures within Sco-Cen, which complements and expands upon previous age determinations in the literature. We also present initial results from the first epoch observations, including the detections of ten stellar companions, of which six were previously unknown. All planetary candidates in the survey will need follow up in second epoch observations, which are part of the allocated observational programme and will be executed in the near future.

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arXiv2019

Upper limits on protolunar disc masses using ALMA observations of directly-imaged exoplanets

The Solar System gas giants are each surrounded by many moons, with at least 50 prograde satellites thought to have formed from circumplanetary material. Just like the Sun is not the only star surrounded by planets, extrasolar gas giants are likely surrounded by satellite systems. Here, we report on ALMA observations of four <40 Myr old stars with directly-imaged companions: PZ Tel, AB Pic, 51 Eri, and $κ$ And. Continuum emission at 1.3 mm is undetected for any of the systems. Since these are directly-imaged companions, there is knowledge of their temperatures, masses and locations. These allow for upper limits on the amount of circumplanetary dust to be derived from detailed radiative transfer models. These protolunar disc models consider two disc sizes: 0.4 and 0.04 times the exoplanet's Hill radius. The former is representative of hydrodynamic simulations of circumplanetary discs while the latter a case with significant radial drift of solids. The more compact case is also motivated by the semi-major axis of Callisto, enclosing Jupiter's Galilean satellites. All upper limits fall below the expected amount of dust required to explain regular satellite systems ($10^{-4}$ times the mass of their central planet). Upper limits are compared with viscous evolution and debris disc models. Our analysis suggests that the non detections can be interpreted as evidence of dust growth beyond metre sizes to form moonetesimals in timescales <10 Myr. This sample increases by 50% the number of ALMA non-detections of young companions available in the literature.

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arXiv2019

The B-Star Exoplanet Abundance Study: a co-moving 16-25 Mjup companion to the young binary system HIP 79098

Wide low-mass substellar companions are known to be very rare among low-mass stars, but appear to become increasingly common with increasing stellar mass. However, B-type stars, which are the most massive stars within ~150 pc of the Sun, have not yet been examined to the same extent as AFGKM-type stars in that regard. In order to address this issue, we launched the ongoing B-star Exoplanet Abundance Study (BEAST) to examine the frequency and properties of planets, brown dwarfs, and disks around B-type stars in the Scorpius-Centaurus (Sco-Cen) association; we also analyzed archival data of B-type stars in Sco-Cen. During this process, we identified a candidate substellar companion to the B9-type spectroscopic binary HIP 79098 AB, which we refer to as HIP 79098 (AB)b. The candidate had been previously reported in the literature, but was classified as a background contaminant on the basis of its peculiar colors. Here we demonstrate that the colors of HIP 79098 (AB)b are consistent with several recently discovered young and low-mass brown dwarfs, including other companions to stars in Sco-Cen. Furthermore, we show unambiguous common proper motion over a 15-year baseline, robustly identifying HIP 79098 (AB)b as a bona fide substellar circumbinary companion at a 345+/-6 AU projected separation to the B9-type stellar pair. With a model-dependent mass of 16-25 Mjup yielding a mass ratio of <1%, HIP 79098 (AB)b joins a growing number of substellar companions with planet-like mass ratios around massive stars. Our observations underline the importance of common proper motion analysis in the identification of physical companionship, and imply that additional companions could potentially remain hidden in the archives of purely photometric surveys.

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arXiv2017

First millimeter detection of the disk around a young, isolated, planetary-mass object

OTS44 is one of only four free-floating planets known to have a disk. We have previously shown that it is the coolest and least massive known free-floating planet ($\sim$12 M$_{\rm Jup}$) with a substantial disk that is actively accreting. We have obtained Band 6 (233 GHz) ALMA continuum data of this very young disk-bearing object. The data shows a clear unresolved detection of the source. We obtained disk-mass estimates via empirical correlations derived for young, higher-mass, central (substellar) objects. The range of values obtained are between 0.07 and 0.63 M$_{\oplus}$ (dust masses). We compare the properties of this unique disk with those recently reported around higher-mass (brown dwarfs) young objects in order to infer constraints on its mechanism of formation. While extreme assumptions on dust temperature yield disk-mass values that could slightly diverge from the general trends found for more massive brown dwarfs, a range of sensible values provide disk masses compatible with a unique scaling relation between $M_{\rm dust}$ and $M_{*}$ through the substellar domain down to planetary masses.

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arXiv2017

Near-infrared scattered light properties of the HR4796A dust ring: a measured scattering phase function from 13.6deg to 166.6deg

HR4796A is surrounded by a debris disc, observed in scattered light as an inclined ring. Past observations raised several questions. First, a strong brightness asymmetry detected in polarized reflected light recently challenged our understanding of scattering by the dust particles in this system. Secondly, the morphology of the ring strongly suggests the presence of planets, although no planets have been detected to date. We obtained high-angular resolution coronagraphic images of the circumstellar environment around HR4796A with VLT/SPHERE during the commissioning of the instrument in May 2014 and during guaranteed-time observations in February 2015. The observations reveal for the first time the entire ring of dust, including the semi-minor axis that was previously hidden either behind the coronagraphic spot or in the speckle noise. We determine empirically the scattering phase function of the dust in the H band from 13.6deg to 166.6deg. It shows a prominent peak of forward scattering, never detected before, for scattering angles below 30deg. We analyse the reflectance spectra of the disc from the 0.95 to 1.6 microns, confirming the red colour of the dust, and derive detection limits on the presence of planetary mass objects. We confirm which side of the disc is inclined towards the Earth. The analysis of the phase function suggests that the dust population is dominated by particles much larger than the observation wavelength, of about 20 microns. Compact Mie grains of this size are incompatible with the spectral energy distribution of the disc, however the observed rise in scattering efficiency beyond 50deg points towards aggregates which could reconcile both observables. We do not detect companions orbiting the star but our high-contrast observations provide the most stringent constraints yet on the presence of planets responsible for the morphology of the dust.

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arXiv2016

SPHERE IRDIS and IFS astrometric strategy and calibration

We present the current results of the astrometric characterization of the VLT planet finder SPHERE over 2 years of on-sky operations. We first describe the criteria for the selection of the astrometric fields used for calibrating the science data: binaries, multiple systems, and stellar clusters. The analysis includes measurements of the pixel scale and the position angle with respect to the North for both near-infrared subsystems, the camera IRDIS and the integral field spectrometer IFS, as well as the distortion for the IRDIS camera. The IRDIS distortion is shown to be dominated by an anamorphism of 0.60+/-0.02% between the horizontal and vertical directions of the detector, i.e. 6 mas at 1". The anamorphism is produced by the cylindrical mirrors in the common path structure hence common to all three SPHERE science subsystems (IRDIS, IFS, and ZIMPOL), except for the relative orientation of their field of view. The current estimates of the pixel scale and North angle for IRDIS are 12.255+/-0.009 milliarcseconds/pixel for H2 coronagraphic images and -1.75+/-0.08 deg. Analyses of the IFS data indicate a pixel scale of 7.46+/-0.02 milliarcseconds/pixel and a North angle of -102.18+/-0.13 deg. We finally discuss plans for providing astrometric calibration to the SPHERE users outside the instrument consortium.

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arXiv2016

SPOTS: The Search for Planets Orbiting Two Stars: II. First constraints on the frequency of sub-stellar companions on wide circumbinary orbits

A large number of direct imaging surveys for exoplanets have been performed in recent years, yielding the first directly imaged planets and providing constraints on the prevalence and distribution of wide planetary systems. However, like most of the radial velocity ones, these surveys generally focus on single stars, hence binaries and higher-order multiples have not been studied to the same level of scrutiny. This motivated the SPOTS (Search for Planets Orbiting Two Stars) survey, which is an ongoing direct imaging study of a large sample of close binaries, started with VLT/NACO and now continuing with VLT/SPHERE. To complement this survey, we have identified the close binary targets in 24 published direct imaging surveys. Here we present our statistical analysis of this combined body of data. We analysed a sample of 117 tight binary systems, using a combined Monte Carlo and Bayesian approach to derive the expected values of the frequency of companions, for different values of the companion's semi-major axis. Our analysis suggest that the frequency of sub-stellar companions in wide orbit is moderately low ($\lesssim $13% with a best value of 6% at 95% confidence level) and not significantly different between single stars and tight binaries. One implication of this result is that the very high frequency of circumbinary planets in wide orbits around post-common envelope binaries, implied by eclipse timing (up to 90% according to Zorotovic & Schreiber 2013), can not be uniquely due to planets formed before the common-envelope phase (first generation planets), supporting instead the second generation planet formation or a non-Keplerian origin of the timing variations.

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arXiv2016

The SPHERE view of the planet-forming disk around HD100546

We image with unprecedented spatial resolution and sensitivity disk features that could be potential signs of planet-disk interaction. Two companion candidates have been claimed in the disk around the young Herbig Ae/Be star HD100546. Thus, this object serves as an excellent target for our investigation of the natal environment of giant planets. We exploit the power of extreme adaptive optics operating in conjunction with the new high-contrast imager SPHERE to image HD100546 in scattered light. We obtain the first polarized light observations of this source in the visible (with resolution as fine as 2 AU) and new H and K band total intensity images that we analyze with the Pynpoint package. The disk shows a complex azimuthal morphology, where multiple scattering of photons most likely plays an important role. High brightness contrasts and arm-like structures are ubiquitous in the disk. A double-wing structure (partly due to ADI processing) resembles a morphology newly observed in inclined disks. Given the cavity size in the visible (11 AU), the CO emission associated to the planet candidate 'c' might arise from within the circumstellar disk. We find an extended emission in the K band at the expected location of 'b'. The surrounding large-scale region is the brightest in scattered light. There is no sign of any disk gap associated to 'b'.

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