scholarly journals Discovery of a warm, dusty giant planet around HIP 65426

2017 ◽  
Vol 605 ◽  
pp. L9 ◽  
Author(s):  
G. Chauvin ◽  
S. Desidera ◽  
A.-M. Lagrange ◽  
A. Vigan ◽  
R. Gratton ◽  
...  
Keyword(s):  
Near Infrared ◽  
Planet Formation ◽  
Giant Planet ◽  
Size Composition ◽  
Interesting Case ◽  
Surface Gravity ◽  
Dual Band ◽  
High Angular Resolution ◽  
High Contrast ◽  
Integral Field Spectrograph

Aims. The SHINE program is a high-contrast near-infrared survey of 600 young, nearby stars aimed at searching for and characterizing new planetary systems using VLT/SPHERE’s unprecedented high-contrast and high-angular-resolution imaging capabilities. It is also intended to place statistical constraints on the rate, mass and orbital distributions of the giant planet population at large orbits as a function of the stellar host mass and age to test planet-formation theories. Methods. We used the IRDIS dual-band imager and the IFS integral field spectrograph of SPHERE to acquire high-contrast coronagraphic differential near-infrared images and spectra of the young A2 star HIP 65426. It is a member of the ~17 Myr old Lower Centaurus-Crux association. Results. At a separation of 830 mas (92 au projected) from the star, we detect a faint red companion. Multi-epoch observations confirm that it shares common proper motion with HIP 65426. Spectro-photometric measurements extracted with IFS and IRDIS between 0.95 and 2.2 μm indicate a warm, dusty atmosphere characteristic of young low-surface-gravity L5-L7 dwarfs. Hot-start evolutionary models predict a luminosity consistent with a 6–12 MJup, Teff = 1300–1600 K and R = 1.5 ± 0.1 RJup giant planet. Finally, the comparison with Exo-REM and PHOENIX BT-Settl synthetic atmosphere models gives consistent effective temperatures but with slightly higher surface gravity solutions of log (g) = 4.0–5.0 with smaller radii (1.0–1.3 RJup). Conclusions. Given its physical and spectral properties, HIP 65426 b occupies a rather unique placement in terms of age, mass, and spectral-type among the currently known imaged planets. It represents a particularly interesting case to study the presence of clouds as a function of particle size, composition, and location in the atmosphere, to search for signatures of non-equilibrium chemistry, and finally to test the theory of planet formation and evolution.

scholarly journals Investigating the young solar system analog HD 95086

2018 ◽  
Vol 617 ◽  
pp. A76 ◽  
Author(s):  
G. Chauvin ◽  
R. Gratton ◽  
M. Bonnefoy ◽  
A.-M. Lagrange ◽  
J. de Boer ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Near Infrared ◽  
Scattered Light ◽  
Spectral Energy Distribution ◽  
Giant Planet ◽  
Giant Planets ◽  
Dual Band ◽  
Spectral Energy ◽  
Semi Major Axis ◽  
Integral Field Spectrograph

Context. HD 95086 (A8V, 17 Myr) hosts a rare planetary system for which a multi-belt debris disk and a giant planet of 4–5 MJup have been directly imaged. Aims. Our study aims to characterize the global architecture of this young system using the combination of radial velocity and direct imaging observations. We want to characterize the physical and orbital properties of HD 95086 b, search for additional planets at short and wide orbits and image the cold outer debris belt in scattered light. Methods. We used HARPS at the ESO 3.6 m telescope to monitor the radial velocity of HD 95086 over two years and investigate the existence of giant planets at less than 3 au orbital distance. With the IRDIS dual-band imager and the IFS integral field spectrograph of SPHERE at VLT, we imaged the faint circumstellar environment beyond 10 au at six epochs between 2015 and 2017. Results. We do not detect additional giant planets around HD 95086. We identify the nature (bound companion or background contaminant) of all point-like sources detected in the IRDIS field of view. None of them correspond to the ones recently discovered near the edge of the cold outer belt by ALMA. HD 95086 b is resolved for the first time in J-band with IFS. Its near-infrared spectral energy distribution is well fitted by a few dusty and/or young L7–L9 dwarf spectral templates. The extremely red 1–4 μm spectral distribution is typical of low-gravity objects at the L/T spectral type transition. The planet’s orbital motion is resolved between January 2015 and May 2017. Together with past NaCo measurements properly re-calibrated, our orbital fitting solutions favor a retrograde low to moderate-eccentricity orbit e = 0.2+0.3−0.2, with a semi-major axis ~52 au corresponding to orbital periods of ~288 yr and an inclination that peaks at i = 141°, which is compatible with a planet-disk coplanar configuration. Finally, we report the detection in polarimetric differential imaging of the cold outer debris belt between 100 and 300 au, consistent in radial extent with recent ALMA 1.3 mm resolved observations.

scholarly journals First scattered light detection of a nearly edge-on transition disk around the T Tauri star RY Lupi

2018 ◽  
Vol 614 ◽  
pp. A88 ◽  
Author(s):  
M. Langlois ◽  
A. Pohl ◽  
A.-M. Lagrange ◽  
A.- L. Maire ◽  
D. Mesa ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Planet Formation ◽  
Scattered Light ◽  
Emission Feature ◽  
Point Sources ◽  
Tauri Star ◽  
Dual Band ◽  
High Angular Resolution ◽  
T Tauri

Context. Transition disks are considered sites of ongoing planet formation, and their dust and gas distributions could be signposts of embedded planets. The transition disk around the T Tauri star RY Lup has an inner dust cavity and displays a strong silicate emission feature. Aims. Using high-resolution imaging we study the disk geometry, including non-axisymmetric features, and its surface dust grain, to gain a better understanding of the disk evolutionary process. Moreover, we search for companion candidates, possibly connected to the disk. Methods. We obtained high-contrast and high angular resolution data in the near-infrared with the VLT/SPHERE extreme adaptive optics instrument whose goal is to study the planet formation by detecting and characterizing these planets and their formation environments through direct imaging. We performed polarimetric imaging of the RY Lup disk with IRDIS (at 1.6 μm), and obtained intensity images with the IRDIS dual-band imaging camera simultaneously with the IFS spectro-imager (0.9–1.3 μm). Results. We resolved for the first time the scattered light from the nearly edge-on circumstellar disk around RY Lup, at projected separations in the 100 au range. The shape of the disk and its sharp features are clearly detectable at wavelengths ranging from 0.9 to 1.6 μm. We show that the observed morphology can be interpreted as spiral arms in the disk. This interpretation is supported by in-depth numerical simulations. We also demonstrate that these features can be produced by one planet interacting with the disk. We also detect several point sources which are classified as probable background objects.

scholarly journals Simulating gas kinematic studies of high-redshift galaxies with the HARMONI integral field spectrograph

2020 ◽  
Vol 498 (2) ◽  
pp. 1891-1904
Author(s):  
Mark L A Richardson ◽  
Laurence Routledge ◽  
Niranjan Thatte ◽  
Matthias Tecza ◽  
Ryan C W Houghton ◽  
...  
Keyword(s):  
Near Infrared ◽  
High Redshift ◽  
Line Emission ◽  
High Angular Resolution ◽  
High Redshift Galaxies ◽  
Gas Kinematics ◽  
Post Process ◽  
Kinematic Studies ◽  
Integral Field Spectrograph ◽  
Integral Field

ABSTRACT We present simulated observations of gas kinematics in a galaxy formed in a 10 pc resolution cosmological simulation with the hydrodynamical +   N-body code ramses, using the new ramses2hsim pipeline with the simulated observing pipeline (hsim) for the Extremely Large Telescope High Angular Resolution Monolithic Optical and Near-infrared Integral field spectrograph (HARMONI IFS). We post-process the galaxy's gas kinematics and Hα line emission for each simulation cell, and integrate the emission to produce an extinction-corrected input cube. We then simulate observations of the input cube with HARMONI, for a range of exposure times, spatial sampling, and spectral resolution. We analyse the mock observations to recover galaxy properties such as its kinematics and compare with the known simulation values. We investigate the cause of biases between the ‘real’ and ‘observed’ kinematic values, demonstrating the sensitivity of the inferred rotation curve to knowledge of the instrument’s point spread function.

scholarly journals New spectro-photometric characterization of the substellar object HR 2562 B using SPHERE

2018 ◽  
Vol 612 ◽  
pp. A92 ◽  
Author(s):  
D. Mesa ◽  
J.-L. Baudino ◽  
B. Charnay ◽  
V. D’Orazi ◽  
S. Desidera ◽  
...  
Keyword(s):  
Near Infrared ◽  
Speckle Noise ◽  
Dual Band ◽  
Physical Parameters ◽  
Atmospheric Models ◽  
Fundamental Properties ◽  
Spectral Bands ◽  
Very Large Telescope ◽  
Integral Field Spectrograph

Aims. HR 2562 is an F5V star located at ~33 pc from the Sun hosting a substellar companion that was discovered using the Gemini planet imager (GPI) instrument. The main objective of the present paper is to provide an extensive characterization of the substellar companion, by deriving its fundamental properties. Methods. We observed HR 2562 with the near-infrared branch composed by the integral field spectrograph (IFS) and the infrared dual band spectrograph (IRDIS) of the spectro-polarimetric high-contrast exoplanet research (SPHERE) instrument at the very large telescope (VLT). During our observations IFS was operating in the Y J band, while IRDIS was observing with the H broadband filter. The data were reduced with the dedicated SPHERE GTO pipeline, which is custom designed for this instrument. On the reduced images, we then applied the post-processing procedures that are specifically prepared to subtract the speckle noise. Results. The companion is clearly detected in both IRDIS and IFS datasets. We obtained photometry in three different spectral bands. The comparison with template spectra allowed us to derive a spectral type of T2–T3 for the companion. Using both evolutionary and atmospheric models we inferred the main physical parameters of the companion obtaining a mass of 32 ± 14 MJup, Teff = 1100 ± 200 K, and log g = 4.75 ± 0.41.

scholarly journals Substructure and Signs of Planet Formation in the Disk of HD 169142

2013 ◽  
Vol 8 (S299) ◽  
pp. 145-148
Author(s):  
M. Osorio ◽  
G. Anglada ◽  
C. Carrasco-González ◽  
J. M. Torrelles ◽  
P. D'Alessio ◽  
...  
Keyword(s):  
Near Infrared ◽  
Planet Formation ◽  
Spectral Energy Distribution ◽  
Broad Band ◽  
Dust Emission ◽  
Central Star ◽  
Physical Structure ◽  
Spectral Energy ◽  
High Angular Resolution ◽  
Compact Source

AbstractWe carried out 7 mm VLA observations at very high angular resolution that reveal substructure and evidence of planet formation in the disk of HD 169142. Our observations, along with near-infrared polarimetric imaging, show that this disk has a ring of enhanced, asymmetric emission at a radius of ~25 AU from the central star. This ring, whose inner region appears devoid of emission, is surrounded by an annular gap in surface density in the ~30-70 AU range of radii. Several mechanisms have been invoked in the literature to explain this kind of gaps and cavities. Among them, one of the most interesting is the possibility that one or more planets in formation are creating these cavities. Since our 7 mm observations show a compact source lying in the 30-70 AU gap, we speculate that this compact source could be tracing dust emission associated with a possible protoplanet. We model the broad-band spectral energy distribution of the disk and we infer its physical structure. From this modeling we infer the presence of a small (r ~ 0.7 AU) disk inside the central cavity, suggesting that the HD 169142 disk is in the pre-transitional disk phase.

scholarly journals Determining mass limits around HD 163296 through SPHERE direct imaging data

2019 ◽  
Vol 488 (1) ◽  
pp. 37-46 ◽  
Author(s):  
D Mesa ◽  
M Langlois ◽  
A Garufi ◽  
R Gratton ◽  
S Desidera ◽  
...  
Keyword(s):  
Near Infrared ◽  
The Other ◽  
Field Of View ◽  
Dual Band ◽  
Imaging Data ◽  
Direct Imaging ◽  
Be Star ◽  
Integral Field Spectrograph ◽  
Ringed Structure ◽  
Integral Field

ABSTRACT HD 163296 is a Herbig Ae/Be star known to host a protoplanetary disc with a ringed structure. To explain the disc features, previous works proposed the presence of planets embedded into the disc. We have observed HD 163296 with the near-infrared (NIR) branch of SPHERE composed by IRDIS (InfraRed Dual-band Imager and Spectrograph) and IFS (integral field spectrograph) with the aim to put tight constraints on the presence of substellar companions around this star. Despite the low rotation of the field of view during our observation we were able to put upper mass limits of few MJup around this object. These limits do not allow to give any definitive conclusion about the planets proposed through the disc characteristics. On the other hand, our results seem to exclude the presence of the only candidate proposed until now using direct imaging in the NIR even if some caution has to be taken considered the different wavelength bands of the two observations.

scholarly journals A giant exoplanet orbiting a very-low-mass star challenges planet formation models

Science ◽  
2019 ◽  
Vol 365 (6460) ◽  
pp. 1441-1445 ◽  
Author(s):  
J. C. Morales ◽  
A. J. Mustill ◽  
I. Ribas ◽  
M. B. Davies ◽  
A. Reiners ◽  
...  
Keyword(s):  
Near Infrared ◽  
Planet Formation ◽  
Giant Planet ◽  
Mass Star ◽  
Low Mass Stars ◽  
Migration Rates ◽  
Low Mass ◽  
And Migration ◽  
Core Accretion ◽  
Planet Accretion

Surveys have shown that super-Earth and Neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. We report the discovery of a giant planet around the very-low-mass star GJ 3512, as determined by optical and near-infrared radial-velocity observations. The planet has a minimum mass of 0.46 Jupiter masses, very high for such a small host star, and an eccentric 204-day orbit. Dynamical models show that the high eccentricity is most likely due to planet-planet interactions. We use simulations to demonstrate that the GJ 3512 planetary system challenges generally accepted formation theories, and that it puts constraints on the planet accretion and migration rates. Disk instabilities may be more efficient in forming planets than previously thought.

scholarly journals Possible evidence of ongoing planet formation in AB Aurigae

2020 ◽  
Vol 637 ◽  
pp. L5 ◽  
Author(s):  
A. Boccaletti ◽  
E. Di Folco ◽  
E. Pantin ◽  
A. Dutrey ◽  
S. Guilloteau ◽  
...  
Keyword(s):  
Near Infrared ◽  
Planet Formation ◽  
Scattered Light ◽  
Density Wave ◽  
Giant Planet ◽  
Wave Model ◽  
Contrast Imaging ◽  
Spiral Arms ◽  
High Contrast Imaging ◽  
Very Large Telescope

Context. Planet formation is expected to take place in the first million years of a planetary system through various processes, which remain to be tested through observations. Aims. With the recent discovery, using ALMA, of two gaseous spiral arms inside the ∼120 au cavity and connected to dusty spirals, the famous protoplanetary disk around AB Aurigae presents a strong incentive for investigating the mechanisms that lead to giant planet formation. A candidate protoplanet located inside a spiral arm has already been claimed in an earlier study based on the same ALMA data. Methods. We used SPHERE at the Very Large Telescope to perform near-infrared high-contrast imaging of AB Aur in polarized and unpolarized light in order to study the morphology of the disk and search for signs of planet formation. Results. SPHERE has delivered the deepest images ever obtained for AB Aur in scattered light. Among the many structures that are yet to be understood, we identified not only the inner spiral arms, but we also resolved a feature in the form of a twist in the eastern spiral at a separation of about 30 au. The twist of the spiral is perfectly reproduced with a planet-driven density wave model when projection effects are accounted for. We measured an azimuthal displacement with respect to the counterpart of this feature in the ALMA data, which is consistent with Keplerian motion on a 4 yr baseline. Another point sxce is detected near the edge of the inner ring, which is likely the result of scattering as opposed to the direct emission from a planet photosphere. We tentatively derived mass constraints for these two features. Conclusions. The twist and its apparent orbital motion could well be the first direct evidence of a connection between a protoplanet candidate and its manifestation as a spiral imprinted in the gas and dust distributions.

scholarly journals VLT/SPHERE survey for exoplanets around young early-type stars, including systems with multi-belt architectures

2020 ◽  
Vol 639 ◽  
pp. A54
Author(s):  
M. Lombart ◽  
G. Chauvin ◽  
P. Rojo ◽  
E. Lagadec ◽  
P. Delorme ◽  
...  
Keyword(s):  
Main Sequence ◽  
Near Infrared ◽  
Giant Planet ◽  
Dual Band ◽  
Debris Disks ◽  
Early Type ◽  
Infrared Images ◽  
Main Sequence Stars ◽  
Direct Imaging ◽  
Early Type Stars

Context. Dusty debris disks around pre- and main-sequence stars are potential signposts for the existence of planetesimals and exoplanets. Giant planet formation is therefore expected to play a key role in the evolution of the disk. This is indirectly confirmed by extant submillimeter near-infrared images of young protoplanetary and cool dusty debris disks around main-sequence stars that usually show substantial spatial structures. With two decades of direct imaging of exoplanets already studied, it is striking to note that a majority of recent discoveries of imaged giant planets have been obtained around young early-type stars hosting a circumstellar disk. Aims. Our aim was to create a direct imaging program designed to maximize our chances of giant planet discovery and target 22 young early-type stars. About half of them show indications of multi-belt architectures. Methods. Using the IRDIS dual-band imager and the IFS integral field spectrograph of SPHERE to acquire high-constrast coronagraphic differential near-infrared images, we conducted a systematic search in the close environment of these young, dusty, and early-type stars. We used a combination of angular and spectral differential imaging to reach the best detection performances down to the planetary mass regime. Results. We confirm that companions detected around HIP 34276, HIP 101800, and HIP 117452 are stationary background sources and binary companions. The companion candidates around HIP 8832, HIP 16095, and HIP 95619 are determined as background contaminations. Regarding the stars for which we infer the presence of debris belts, a theoretical minimum mass for planets required to clear the debris gaps can be calculated. The dynamical mass limit is at least 0.1 MJ and can exceed 1 MJ. Direct imaging data is typically sensitive to planets down to ~3.6 MJ at 1′′, and 1.7 MJ in the best case. These two limits tightly constrain the possible planetary systems present around each target. These systems will be probably detectable with the next generation of planet imagers.

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